Research Publications

@article{348,

title = {Investigation of structural and electrochemical properties of Triphala-ZnO nanocomposite synthesized via green methodology for supercapacitor applications},

author = {S. Vigneshwaran and C. Naveen and H. Premkumar and R. Aswini and M. Priyanka and M. Muthuvinayagam and P. Rameshkumar and M. V. Pillai and A. H. Hirad and S. Arunachalam},

url = {https://link.springer.com/article/10.1007/s11581-024-06037-8},

doi = {10.1007/s11581-024-06037-8},

isbn = {09477047 (ISSN)},

year  = {2025},

date = {2025-02-01},

journal = {Ionics},

volume = {31},

publisher = {Springer Science and Business Media Deutschland GmbH},

chapter = {2123–2135},

abstract = {In the rapidly evolving world, the demand for energy storage solutions is escalating due to factors such as population growth, industrialization, and technological advancements. This research explores the potential of Triphala-ZnO nanocomposite powder as a novel material for energy storage applications. Triphala, a traditional Ayurvedic herbal formulation, is combined with zinc oxide (ZnO) nanoparticles to form a nanocomposite using a simple and cost-effective co-precipitation method. The structural, morphological, and compositional properties of the synthesized Triphala-ZnO nanocomposite were confirmed through characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), and Fourier transform infrared spectroscopy (FTIR). The electrochemical studies, including cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) analysis, revealed the performance of synthesized material. In CV analysis, carried out with a 3 M KOH electrolyte, showed a specific capacitance of 511.7 F g⁻1 at 10 mV s⁻1 and a specific energy density of 279.90 Wh kg. In GCD analysis, the nanocomposite exhibited a specific capacitance of 8.11 F g⁻1 at a current density of 1 A g⁻1. These variations suggest the material exhibits pseudocapacitive characteristics. Moreover, the nanocomposite demonstrated an ionic conductivity of 1.6 × 10⁻3 S/cm and a low internal resistance of 5.9 Ω. The significant enhancement in specific capacitance and energy density compared to pure Triphala underscores the superior potential of the Triphala-ZnO nanocomposite for next-generation energy storage systems.},

note = {0},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{701,

title = {Characterization of Polypyrrole Based Novel High Dielectric Materials for Low Frequency Applications},

author = {L. B. Gunjal and S. Manjunatha and C. H. V. V. Ramana and P. N. R. Shankar and H. L. Pushpalatha and Y. T. Ravikiran and N. M. Nagabhushana},

url = {https://link.springer.com/article/10.1007/s42341-025-00686-w},

doi = {10.1007/s42341-025-00686-w},

isbn = {12297607 (ISSN); 20927592 (ISSN)},

year  = {2025},

date = {2025-01-01},

journal = {Transactions on Electrical and Electronic Materials},

publisher = {Korean Institute of Electrical and Electronic Material Engineers},

abstract = {Neodymium oxide (Nd<inf>2</inf>O<inf>3</inf>) embedded in polypyrrole (PPy) with varying compositions were synthesized using the chemical polymerization technique. PPy and PPy/Nd<inf>2</inf>O<inf>3</inf> composites were employed to the several characterization techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) studies. Room temperature AC conductivity studies were carried out in the frequency range 50 Hz to 5 MHz. PPy/Nd<inf>2</inf>O<inf>3</inf>-10 wt% composite exhibited highest conductivity of 2.69 × 10−² Scm− 1 among all the composites and an increase of two orders compared to PPy, which is noteworthy. Cole-Cole plots for the composites exhibited a non-Debye type relaxation. Interestingly, dielectric constant of PPy/Nd<inf>2</inf>O<inf>3</inf>-10 wt% composite in the frequency range 1–100 kHz was found to be high ≈ 1000. Also, the low frequency relaxation peaks, low dielectric loss of the composites makes them potential candidates in the design of low frequency operating devices.},

note = {0},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{682,

title = {Neodymium Oxide Embedded Polypyrrole Matrix for Humidity Sensing Applications},

author = {L. B. Gunjal and S. Manjunatha and P. N. Shankar and A. Sunilkumar and Y. T. Ravikiran and H. L. Pushpalatha and N. M. Nagabhushana},

url = {https://www.tandfonline.com/doi/full/10.1080/25740881.2025.2560912},

doi = {10.1080/25740881.2025.2560912},

isbn = {2574089X (ISSN); 25740881 (ISSN)},

year  = {2025},

date = {2025-01-01},

journal = {Polymer-Plastics Technology and Materials},

volume = {64},

pages = {2701-2712,},

publisher = {Taylor and Francis Ltd.},

abstract = {In-situ chemical polymerization was employed to synthesize a polypyrrole matrix embedded with rare earth oxide, resulting in the formation of polypyrrole-neodymium oxide (PPy/Nd<inf>2</inf>O<inf>3</inf>) composites with varying weight percentages of Nd<inf>2</inf>O<inf>3</inf> (10, 30, and 50). The crystalline properties of these composites were elucidated through XRD spectra. The SEM images of the PPy/Nd<inf>2</inf>O<inf>3</inf> − 50% composite indicated a uniform distribution of Nd<inf>2</inf>O<inf>3</inf> within the PPy matrix, characterized by smaller grain sizes. Furthermore, TEM analyses corroborated the crystalline structure of the composite, confirming the incorporation of Nd<inf>2</inf>O<inf>3</inf> within the PPy matrix. FTIR spectra demonstrated the interfacial interactions between PPy and Nd<inf>2</inf>O<inf>3</inf>, as well as the composite’s formation. The composites’ capacity to detect humidity was assessed across a relative humidity spectrum of 10% to 97%. Notably, the PPy/Nd2O3–50% composite exhibited a rapid response time of 30 seconds and a recovery duration of 34 seconds, alongside commendable linearity (0.9991), sensitivity, and detection limits.},

note = {0},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{647,

title = {Green Synthesis of Silver-Doped NiO Nanoparticles for Photocatalytic and Electrochemical Sensor Applications from Neem Leaf Latex},

author = {Naveen Kumar and M. Balakrishna and S. Sudhakar and U. Desai and N. Naik},

url = {https://link.springer.com/article/10.1007/s11244-025-02190-0},

doi = {10.1007/s11244-025-02190-0},

isbn = {10225528 (ISSN); 15729028 (ISSN)},

year  = {2025},

date = {2025-01-01},

journal = {Topics in Catalysis},

publisher = {Springer},

abstract = {Neem (Azadirachta indica) leaf extract was used to create pure NiO and Ag-doped NiO nanoparticles (Ag-NiO NPs) of 1, 3, and 5 mol% by solution combustion method at 400 °C and calcining at 1000 °C for two hours. The synthesized Ag-NiO NPs were comprehensively characterized using various analytical techniques, including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM/HRTEM), Selected Area Electron Diffraction (SAED) and UV-diffuse reflectance spectroscopy (UV-DRS). Powder X-ray diffraction (PXRD) analysis confirmed their cubic crystal structure with a space group of Fm-3m. The average crystallite size of 25 nm. The bandgap energy for pure NiO, 1%, 3%, and 5% Ag doped NPs is to be 4.08, 4.05, 3.96, and 3.84 eV. The 3% Ag-doped NiO showed strong photocatalytic activity in breaking down Fast Blue (FB) and Acid Orange Red (AOR) dyes, with absorption peaks at 622 nm and 484 nm, respectively. After 120 min of UV light exposure, a significant reduction in dye concentration was observed, confirming the material’s effectiveness for photocatalytic applications. Excellent redox potential output was determined by cyclic voltammetry (CV) in an electrochemical evaluation of the produced material using graphite electrode paste in 1 M KOH electrolyte. Electrochemical impedance spectroscopy (EIS) research has demonstrated that the decreased charge transfer resistance of Ag-NiO NPs is responsible for their improved behaviour. After computation, it was discovered that the Ag-NiO NPs -specific capacitance values were 125.7 Fg−1 at a scan rate of 50 mVs−1. The paracetamol and penegra materials were effectively sensed by the prepared carbon paste electrode of Ag-NiO NPs (3 mol%) as revealed by cyclic voltammetric and EIS studies. All the above results show that the synthesized Ag-NiO (3%) NPs can be a potential candidate for waste water treatment and electrochemical sensor applications.},

note = {0},

keywords = {Cyclic voltammetry, PHY},

pubstate = {published},

tppubtype = {article}

}

@article{631,

title = {Bluish-green luminescence and electrochemical properties of cerium-doped zinc chromite nanoparticles for display and energy storage applications},

author = {M. M and Y. S. Vidya and H. C. Manjunatha and R. Munirathnam and S. Manjunatha and M. Shivanna and S. Kumar and E. Krishnakanth},

url = {https://link.springer.com/article/10.1007/s10854-025-15737-4},

doi = {10.1007/s10854-025-15737-4},

isbn = {09574522 (ISSN); 1573482X (ISSN)},

year  = {2025},

date = {2025-01-01},

journal = {Journal of Materials Science: Materials in Electronics},

volume = {36},

publisher = {Springer},

abstract = {Cerium-doped zinc chromite (ZnCr<inf>2</inf>O<inf>4</inf>:Ce) nanoparticles were synthesized using the Solution Combustion Method (SCM), employing Aloe vera gel extract as a green fuel. Post-synthesis calcination at 500 °C for 3 h enhanced crystallinity. X-ray diffraction confirmed the formation of a single-phase cubic spinel structure (space group Fd-3m), with crystallite size decreasing from 15.56 to 12.06 nm at 9 mol% Ce3+, as determined by Scherrer’s formula. Transmission Electron Microscopy corroborated these results, revealing well-dispersed nanoparticles and nanorods. UV–Vis spectroscopy indicated a band gap reduction from 2.98 to 2.94 eV with increasing Ce3+ content, attributed to dopant-induced localized states. Photoluminescence under 238 nm excitation showed a strong emission at 490 nm and weaker emissions at 726 and 736 nm. Emission intensity peaked at 7 mol% Ce3+ before decreasing at 9 mol%, confirming concentration quenching. CIE chromaticity coordinates and correlated color temperature (CCT) analysis verified bluish-green (aqua) emission, suitable for indoor lighting. Electrochemical characterization demonstrated promising energy storage behavior. Cyclic voltammetry showed clear redox peaks, and EIS revealed low charge–transfer resistance, indicating efficient ion transport. Galvanostatic charge–discharge measurements yielded specific capacitance values ranging from 84.29 F/g (undoped) to a maximum of 123.41 F/g at 5 mol% Ce3+, with a decline at higher doping levels due to structural distortion. Overall, the Ce3+-doped ZnCr<inf>2</inf>O<inf>4</inf> nanoparticles exhibit tunable optical and electrochemical properties, making them strong candidates for multifunctional applications in energy storage systems and optoelectronic devices.},

note = {0},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{476,

title = {Green engineered zinc chromite doped with Sm3+ nanoparticles: Structural, photoluminescence and supercapacitor properties},

author = {M. Priyanka and Y. S. Vidya and H. C. Manjunatha and R. Munirathnam and S. Manjunatha and M. Shivanna and S. Kumar and E. Krishnakanth},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0921510725005276?via%3Dihub},

doi = {10.1016/j.mseb.2025.118503},

isbn = {09215107 (ISSN)},

year  = {2025},

date = {2025-01-01},

journal = {Materials Science and Engineering: B},

volume = {322},

publisher = {Elsevier Ltd},

abstract = {This groundbreaking research successfully synthesized Samarium-doped ZnCr2O4 nanoparticles (NPs) using the solution combustion method. Aloe vera gel extract is used as a reducing agent. As-formed samples are subjected to calcination at 500 °C for 3 h. X-ray diffraction analysis unambiguously proved pure cubic spinel structure. Notably, increasing the dopant concentration led to a drop in crystallite size from 13.89 ± 1.3 to 11.58 ± 1.1 nm. TEM image shows the existence of agglomerated irregularly shaped NPs and the evaluated crystallite size matches with Scherrer's method. SEM images clearly indicates the formation of smaller, longer length nanorods and irregular size and shaped NPs with an increase in dopant quantity. The energy band gap (Eg) reduced from 2.91 to 2.87 eV. Photoluminescence (PL) measurements under a 293 nm excitation wavelength revealed a pronounced emission peak at 592 nm. The concentration quenching was observed at a 5 mol% doping concentration. The CIE and CCT coordinates unequivocally verified the orange red emission which can be attributed to 4G5/2→ 6H7/2 transition of Sm3+ within the host lattice, providing a warmer appearance advisable for indoor lighting applications. Electrochemical analyses, including cyclic voltammetry, were performed to elucidate redox reactions, electrode kinetics, and electrochemical behavior. Ion transport kinetics were precisely determined through Electrochemical Impedance Spectroscopy, while supercapacitance values were assessed via Galvanostatic Charge–Discharge studies. Impressively, the supercapacitance values ranged from 89.35 and 130.92 F/g, highlighting their remarkable sensitiveness to dopant quantity. Thus, the NPs produced in this pioneering study holds promising applications in the realm of energy storage materials and in display technology.},

note = {0},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{431,

title = {Enhanced red luminescence, Judd–Ofelt intensity parameters and supercapacitor properties of Europium doped zinc chromite nanoparticles synthesized via green mediated combustion route},

author = {M. Priyanka and Y. S. Vidya and H. C. Manjunatha and R. Munirathnam and S. Manjunatha and M. Shivanna and S. Kumar and E. Krishnakanth},

url = {https://link.springer.com/article/10.1007/s00339-025-08520-z},

doi = {10.1007/s00339-025-08520-z},

isbn = {09478396 (ISSN)},

year  = {2025},

date = {2025-01-01},

journal = {Applied Physics A: Materials Science and Processing},

volume = {131},

publisher = {Springer Science and Business Media Deutschland GmbH},

abstract = {In the current communication, for the first time, Europium doped (1–9 mol%) Zinc chromite nanopar- ticles (NPs) were synthesized by solution combustion method using AloeV era gel extract as a reduc- ing agent followed by calcination at 500 °C for 3 h. The Bragg reflections confirms the formation of cubic spinel structure and also the absence of other impurities. The crystallite size estimated from Scherrer’s method found to decrease from 14.11 to 5.37 nm with increase in dopant concentration. The surface morphology consists irregular shaped agglomerated Nps. The energy band gap found to decrease from 2.95 to 2.89 eV. Further, photoluminescence spectra was recorded under 400 nm exci- tation wavelength consists characteristics peaks of Eu3+. The concentration quenching is observed at 7 mol% which might be due to dipole–dipole transition. The CIE and CCT coordinates clearly confirms the red emission of Eu3+ within the host lattice with warmer appearance and finds an application in residential, hospital etc. The Judd–Ofelt intensity parameters and their derivatives like radiative transition probability, radiative lifetime, branching ratio, and the asymmetry ratio are calculated. The cyclic voltametry analysis were also carried out to know the redox reactions, electrode kinetics, and electrochemical behavior. Ion transport kinetics were elucidated through Electrochemical Impedance Spectroscopy (EIS), while the determination of super capacitance val- ues was accomplished via Galvanostatic Charge–Discharge (GCD) analysis. The super capacitance value was found to be in the range 81.84 to 119.82 F/g with increase in dopant concentration. Hence, the material synthesized in this study holds promise for applications in both energy storage materials and the field of display technology.},

note = {0},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{368,

title = {Effect of terbium concentration on green emission and supercapacitance properties of Zinc chromite nanoparticles},

author = {P. M. and Y. S. Vidya and H. C. Manjunatha and R. Munirathnam and S. Manjunatha and M. Shivanna and S. Kumar and E. Krishnakanth and L. Seenappa},

doi = {10.1016/j.inoche.2024.113776},

isbn = {13877003 (ISSN)},

year  = {2025},

date = {2025-01-01},

journal = {Inorganic Chemistry Communications},

volume = {173},

publisher = {Elsevier B.V.},

abstract = {We synthesized Terbium-doped Zinc chromite nanoparticles (NPs) using the solution combustion method (SCM), followed by calcination at 500 °C for 3 h. XRD analysis confirmed the formation of a cubic spinel structure with extreme purity. Increasing the Tb quantity decreased the crystallite size from 26 to 12.14 nm. Surface morphology showed a mix of irregularly shaped NPs and nanorods. Eg decreased from 3.01 to 2.95 eV. Photoluminescence measurements at 277 nm excitation revealed an emission peak at 554 nm, with concentration quenching at 7 mol%. CIE and CCT coordinates confirmed green emission, suitable for outdoor lighting. Electrochemical analysis using cyclic voltammetry showed super capacitance values ranging from 99.03 to 144.92 F/g, sensitive to Tb quantity. This material shows promise for energy storage and display technology applications. © 2024 Elsevier B.V.},

note = {0},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{268,

title = {AC conductivity studies in copper decorated and zinc oxide embedded polypyrrole composite nanorods: Interfacial effects},

author = {R. Megha and Y. T. Ravikiran and S. C. Kumari and H. G. Rajprakash and S. Manjunatha and M. Revanasiddappa and M. Prashantkumar and S. Thomas},

doi = {10.1016/j.mssp.2020.104963},

isbn = {13698001 (ISSN)},

year  = {2020},

date = {2020-01-01},

journal = {Materials Science in Semiconductor Processing},

volume = {110},

pages = {104963+},

publisher = {Elsevier Ltd},

abstract = {In this work, synthesis, characterization and temperature dependent alternating current (AC) conductivity studies on copper decorated and zinc oxide embedded polypyrrole (PPy/Cu–ZnO) ternary composite nanorods are reported. The composite nanorods were prepared by mechanical mixing of chemically synthesized copper decorated polypyrrole (PPy/Cu composite) with zinc oxide (ZnO). The so prepared nanorods were thoroughly characterized using TEM, SEM, FTIR and XRD techniques. Significant morphological change in the form of solid nanorods of the ternary composite was confirmed from its TEM image. The surface morphology of the composite nanorods was shown to be porous hinting that these nanorods have good prospects for gas sensing applications. The AC conductivities of PPy, PPy/Cu composite and PPy/Cu–ZnO composite nanorods were studied in the frequency range 100 Hz to 5 MHz over a temperature range 303 K–373 K. The increased AC conductivity of the composite nanorods as compared to those of PPy/Cu composite and PPy is discussed on the basis of interfacial effects and supported theoretically on the basis of correlated barrier hopping (CBH) model. © 2020 Elsevier Ltd},

note = {26},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{266,

title = {Humidity sensing performance of hybrid nanorods of polyaniline-Yttrium oxide composite prepared by mechanical mixing method},

author = {B. Chethan and H. G. Prakash and Y. T. Ravikiran and S. C. Kumari and S. Manjunatha and S. Thomas},

doi = {10.1016/j.talanta.2020.120906},

isbn = {00399140 (ISSN)},

year  = {2020},

date = {2020-01-01},

journal = {Talanta},

volume = {215},

pages = {120906+},

publisher = {Elsevier B.V.},

abstract = {In this work, polyaniline (PANI) synthesized by in-situ polymerization was mechanically mixed with different feeding mass ratios of Y2O3 to form four Polyaniline/Yttrium oxide (PYO) composites. Among them, the PYO-4 composite acquiring nanorod structure with high aspect ratio confirmed from its TEM image and consequent maximum enhancement in its humidity sensing response discussed in comparison with those of PANI and other composites. The interaction of PANI with Y2O3 in the composite confirmed from FTIR studies. The increase in defects and vacancies in all the composites, being maximum in PYO-4 composite nanorods compared to those of PANI confirmed from XRD studies. Maximum increase in the porosity of PYO-4 composite nanorods as compared to those of PANI and other composites confirmed from SEM studies. The humidity sensing studies revealed that, PYO-4 composite nanorods showed a maximum sensing response of 99.99% with a dynamic response and recovery time of 3 s and 4 s respectively. The PYO-4 composite nanorods having acquired comparatively good sensing characteristics such as low real sensitivity and limit of detection (LOD), negligible hysteresis, best linearity and perfect stability as against those of PANI and other composites established which were also correlated with the calculated physical parameters such as porosity, water content and degree of swelling. © 2020 Elsevier B.V.},

note = {49},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{143,

title = {Influence of electron beam irradiation on structural, thermo and photoluminescence properties of SrTiO3:Sm3+ nanophosphor},

author = {S. Yeshodamma and K. Hareesh and H. Nagabhushana and J. Dwivedi and V. C. Petwal and D. V. Sunitha},

doi = {10.1016/j.ijleo.2020.165483},

isbn = {00304026 (ISSN)},

year  = {2020},

date = {2020-01-01},

journal = {Optik},

volume = {223},

pages = {165483+},

publisher = {Elsevier GmbH},

abstract = {Solution combustion synthesis (SCS) is employed for the synthesis of SrTiO3:Sm3+ (0−11 mol%) nanophosphors. The Powder X-ray diffraction (PXRD) confirms the formation of highly crystalline SrTiO3:Sm3+ nanophosphor assigned to the which was athe standard JCPDs number card 35-0734. Further, the synthesized samples are irradiated by 9 MeV electron beam (10–50 kGy) and analysed using Fourier Transform Infrared (FTIR) spectroscopy and Raman spectroscopic studies to understand the change in chemical properties. PL spectra of pristine sample exhibits emission peaks at 552, 607 and 732 nm wherein irradiated samples 552 and 732 nm peaks vanishes due to loss of crystallinity by irradiation. Further, two TL glow peaks are observed at 192 and 358 °C in E-beam irradiated samples which shows linear L response with dose. The linear TL response is attributed to release of more number of charge carriers and trap density. The kinetic parameters estimated shows simple trap distribution making SrTiO3: Sm3+(3 mol %) nanophosphor good material for radiation dosimetry applications. © 2020 Elsevier GmbH},

note = {2},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{264,

title = {Polyaniline based stable humidity sensor operable at room temperature},

author = {S. Manjunatha and T. Machappa and Y. T. Ravikiran and B. Chethan and A. Sunilkumar},

doi = {10.1016/j.physb.2019.02.063},

isbn = {09214526 (ISSN)},

year  = {2019},

date = {2019-01-01},

journal = {Physica B: Condensed Matter},

volume = {561},

pages = {170-178,},

publisher = {Elsevier B.V.},

abstract = {Humidity sensing behavior of polyaniline-tantalum disulfide (PANI/TaS2), a hybrid material/composite studied in the range of relative humidity 10–97%. The material under study was synthesized using in situ chemical polymerization technique with varying wt% of TaS2 in PANI (10, 30 and 50%). XRD pattern of 50 wt% composite revealed amorphous nature of the synthesized hybrid and its FTIR spectrum showed the interaction between PANI and TaS2. TGA established the thermal stability of the composite at the elevated temperatures. Scanning and transmission electron microscopy images evidenced the encapsulated structures of the composite. Porous nature has facilitated and enhanced the humidity sensing properties of the composites. Change in resistance of the material with the increase in relative humidity, exhibited a good linearity in the relative humidity range. PANI/TaS2 -50% composite performed maximum sensing response of 97% and recorded a good response and recovery times of 36 and 49 s respectively with a low humidity hysteresis loss. Stable sensing ability of the composite was tested over a period of one month. © 2019 Elsevier B.V.},

note = {67},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{263,

title = {Effect of holmium oxide on impedance and dielectric behavior of polyaniline–holmium oxide composites},

author = {S. Manjunatha and A. Sunilkumar and Y. T. Ravikiran and T. Machappa},

doi = {10.1007/s10854-019-01371-4},

isbn = {09574522 (ISSN)},

year  = {2019},

date = {2019-01-01},

journal = {Journal of Materials Science: Materials in Electronics},

volume = {30},

pages = {10332-10341,},

publisher = {Springer New York LLC},

abstract = {Applying chemical in situ polymerization method, conducting polyaniline–holmium oxide (PANI/Ho2O3) composites with varying wt% of Ho2O3 in PANI were prepared. Composites were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and transmission electron microscopy. Room temperature frequency response conductivity and the dielectric studies of the as synthesized composites were investigated in the range 50 to 106 Hz. AC conductivity was found to decrease with the increasing wt% of Ho2O3. Further, conductivity of the composites obeyed power law of disordered materials. Cole–Cole plots for each composite, depicted single semicircle inferring that the conduction is due to the hopping of charge carriers. With increasing wt% of Ho2O3, dielectric constant and dielectric loss both decreased and at low frequencies, high dielectric constant of the composites, found decreasing with increasing applied frequencies due to Maxwell–Wagner type polarization. Tangent loss plots showed relaxation peaks at the resonant frequency. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.},

note = {26},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{259,

title = {Polypyrrole–Tantalum disulfide composite: An efficient material for fabrication of room temperature operable humidity sensor},

author = {A. Sunilkumar and S. Manjunatha and B. Chethan and Y. T. Ravikiran and T. Machappa},

doi = {10.1016/j.sna.2019.111593},

isbn = {09244247 (ISSN)},

year  = {2019},

date = {2019-01-01},

journal = {Sensors and Actuators, A: Physical},

volume = {298},

pages = {111593+},

publisher = {Elsevier B.V.},

abstract = {Polypyrrole-tantalum disulfide (PPy/TaS2) composites were synthesized with varying wt% of TaS2 (10, 30 and 50) by in situ chemical polymerization. XRD spectra of the composites unraveled their crystalline nature. SEM images of the PPy/TaS2-50% composite inferred the uniform distribution of TaS2 in the matrix of PPy with reduced grain size. TaS2 sheets embedded in the PPy matrix and crystalline nature of the composite confirmed from TEM studies. FTIR analysis revealed strong interaction between PPy and TaS2. Humidity sensing performances of the composites were studied in the range of 10–97% RH. Among the composites synthesized, PPy/TaS2-50% composite exhibited good linearity, sensitivity, limit of detection along with a sharp response and recovery times of 10 and 20 s respectively. The sensing mechanism has been discussed on the basis of Grotthuss reaction. © 2019 Elsevier B.V.},

note = {44},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{252,

title = {Room temperature humidity sensing behaviour of silver decorated polyaniline composite},

author = {K. Vinay and M. Revanasiddappa and S. Manjunatha and K. Shivakumar and Y. T. Ravikiran},

doi = {10.1088/2053-1591/ab3624},

isbn = {20531591 (ISSN)},

year  = {2019},

date = {2019-01-01},

journal = {Materials Research Express},

volume = {6},

pages = {104003+},

publisher = {Institute of Physics Publishing},

abstract = {The present work is an investigation of humidity sensing response of silver decorated polyaniline composite prepared by in situ chemical oxidative interfacial polymerization using ammonium peroxydisulfate as an oxidant at 0 °C-4 °C. The structural characterization of the samples was examined using FT-IR, XRD, SEM and TEM techniques. The characteristic stretching frequencies in FT-IR spectra are notably shifted towards lower frequency side indicating van der Waals forces of interaction between the interfacial polyaniline (PANI) chain and the silver particles. The surface morphology of the synthesized composite show that, the silver particles appears to be embedded in the PANI matrix. Humidity response measurements of thin free-standing films were carried out by using Mextech-DT-615 instrument at 25 °C. It is observed that there is a decrease in the resistance of the composite with the increase in relative humidity, quick response and recovery times, their sensing performance stability; all revealed their potential candidature for the humidity sensing applications. © 2019 IOP Publishing Ltd.},

note = {12},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{250,

title = {A tungsten disulphide–polypyrrole composite-based humidity sensor at room temperature},

author = {A. Sunilkumar and S. Manjunatha and T. Machappa and B. Chethan and Y. T. Ravikiran},

doi = {10.1007/s12034-019-1955-5},

isbn = {02504707 (ISSN)},

year  = {2019},

date = {2019-01-01},

journal = {Bulletin of Materials Science},

volume = {42},

pages = {271+},

publisher = {Indian Academy of Sciences},

abstract = {An electrically conductive polypyrrole–tungsten disulphide (PPy/WS 2) composite was synthesized by a chemical polymerization technique. The composite was characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX). FESEM images showed the grainy morphology with permeable nature. XRD and FTIR characteristic peak analysis exhibited semi-crystalline behaviour and confirming the interfacial interaction of the as-synthesized composite. EDX confirmed the presence of carbon, nitrogen, oxygen, tungsten and sulphur in the composite. The humidity sensing property of the PPy/WS 2-50% composite was tested and an approximate linear decrease in resistance was observed with an increase in relative humidity, along with a maximum sensing response of 97% and a response-recovery time of 52 and 58 s, respectively. The sensing ability of the composite was observed to be stable, when monitored for a period of two months. © 2019, Indian Academy of Sciences.},

note = {29},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{242,

title = {Room temperature humidity sensing performance of polyaniline–holmium oxide composite},

author = {S. Manjunatha and T. Machappa and Y. T. Ravikiran and B. Chethan and M. Revanasiddappa},

doi = {10.1007/s00339-019-2638-1},

isbn = {09478396 (ISSN)},

year  = {2019},

date = {2019-01-01},

journal = {Applied Physics A: Materials Science and Processing},

volume = {125},

pages = {361+},

publisher = {Springer Verlag},

abstract = {Polyaniline-holmium oxide composite was synthesized using in situ chemical polymerization method. The composite was characterized by spectroscopic techniques such as XRD, FTIR and Raman, whereas morphology was studied by FESEM, TEM and the thermal stability by TGA. The composite under study was tested for humidity sensing characteristics, which exhibited a linear behavior of resistivity with rise in relative humidity from 11 to 97% RH. Maximum humidity sensing response was found to be 95% at 97% RH, with the improved limit of detection of 7.68 with that of polyaniline (12.06), along with a fairly response and recovery times of 32 and 46 s, respectively, very low humidity hysteresis loss of 1.2% and a stable performance over a period of 1 month were indeed remarkable. Sensing mechanism of the composite has been discussed using Grotthuss reaction. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.},

note = {35},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{239,

title = {Squeezing, sub-Poissonian and total noise in degenerate six-wave mixing process},

author = {B. K. Choudhary and D. K. Giri},

doi = {10.12693/APhysPolA.134.1108},

isbn = {05874246 (ISSN)},

year  = {2018},

date = {2018-01-01},

journal = {Acta Physica Polonica A},

volume = {134},

pages = {1108-1114,},

publisher = {Polish Academy of Sciences},

abstract = {We study a single-mode squeezing, sub-Poissonian and total noise in degenerate six-wave mixing process. We establish the analytic expression of first-order and second-order squeezing in terms of total noise under short-time approximation in degenerate six-wave mixing process. It shows that higher-order squeezing allows a much larger fractional noise reduction than lower-order squeezing. We observe that the squeezed states are associated with large number of photons. We find that squeezing is greater in stimulated process than corresponding squeezing in spontaneous interaction. The photon statistics of the pump mode in the process is investigated and found to be sub-Poissonian in nature. The effect of sub-Poissonian nature of an optical field in terms of total noise is also incorporated. We show that the depth of nonclassicality directly depends on the amount of total noise present in the system. This suggests that the more squeezed the state is, the greater is its total noise in the system. © 2018 The Physiological Society of Japan. All Rights Reserved.},

note = {2},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{317,

title = {Synthesis, characterization and photoluminescence properties of CaSiO 3:Eu3+ red phosphor},

author = {H. Nagabhushana and B. M. Nagabhushana and Madesh Kumar and K. V. R. Murthy and C. Shivakumara and R. P. S. Chakradhar},

doi = {10.1016/j.saa.2010.08.063},

isbn = {13861425 (ISSN)},

year  = {2011},

date = {2011-01-01},

journal = {Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy},

volume = {78},

pages = {64-69,},

abstract = {CaSiO3:Eu3+ (1-5 mol%) red emitting phosphors have been synthesized by a low-temperature solution combustion method. The phosphors have been well characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and optical spectroscopy. PXRD patterns reveal monoclinic CaSiO3 phase can be obtained at 900 °C. The SEM micrographs show the crystallites with irregular shape, mostly angular. Upon 254 nm excitation, the phosphor show characteristic fluorescence 5D0 → 7F J (J = 0, 1, 2, 3, 4) of the Eu3+ ions. The electronic transition located at 614 nm corresponding to 5D0 → 7F2 of Eu3+ ions, which is stronger than the magnetic dipole transition located at 593 nm corresponding to 5D 0 → 7F1 of Eu3+ ions. Different pathways involved in emission process have been studied. Concentration quenching has been observed for Eu3+ concentration > 4 mol%. UV-visible absorption shows an intense band at 240 nm in undoped and 270 nm in Eu3+ doped CaSiO3 which is attributed to oxygen to silicon (O-Si) ligand-to-metal charge-transfer (LMCT) band in the SiO3 2- group. The optical energy band gap is widened with increase of Eu3+ ion dopant. © 2010 Elsevier B.V. All rights reserved.},

note = {77},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}

@article{318,

title = {Synthesis, characterization and photoluminescence properties of CaSiO 3: Dy3+ nanophosphors},

author = {H. Nagabhushana and B. M. Nagabhushana and M. Kumar and H. B. Premkumar and C. Shivakumara and R. P. S. Chakradhar},

doi = {10.1080/14786435.2010.491810},

isbn = {14786443 (ISSN)},

year  = {2010},

date = {2010-01-01},

journal = {Philosophical Magazine},

volume = {90},

pages = {3567-3579,},

abstract = {CaSiO3 : Dy3+ (1-5 mol. %) nanophosphors were synthesized by a simple low-temperature solution combustion method. Powder X-ray diffraction patterns revealed that the phosphors are crystalline and can be indexed to a monoclinic phase. Scanning electron micrographs exhibited faceted plates and angular crystals of different sizes with a porous nature. Photoluminescence properties of the Dy3+-doped CaSiO3 phosphors were observed and analyzed. Emission peaks at 483, 573 and 610 nm corresponding to Dy3+ were assigned as 4F9/2 6H15/2, 4F9/2 6H 13/2 and 4F9/2 6H11/2 transitions, respectively, and dominated by the Dy3+ 4F9/2 6H13/2 hyperfine transition. Experimental results revealed that the luminescence intensity was affected by both heat treatment and the concentration of Dy3+ (1-5 mol. %) in the CaSiO3 host. Optimal luminescence conditions were achieved when the concentration of Dy3+ was 2 mol. %. UV-visible absorption features an intense band at 240 nm, which corresponds to an O-Si ligand-to-metal charge transfer band in the [image omitted] group. The optical energy band gap for the undoped sample was found to be 5.45 eV, whereas in Dy3+-doped phosphors it varies in the range 5.49-5.65 eV. The optical energy gap widens with increase of Dy3+ ion dopant. © 2010 Taylor & Francis.},

note = {26},

keywords = {PHY},

pubstate = {published},

tppubtype = {article}

}