Deepti Jain

Simple and precise thermoelectric power measurement setup for different environments.

We report here on a simple but precise thermoelectric power measurement setup that can be adapted for different environments. This setup has been extensively used for cryogen-free environment to measure a variety of samples. It is made simple to load and hold the sample between two copper blocks by a spring-shaft arrangement. The usable range of measurements is a few microV/K to a few hundreds of microV/K. The salient features of the setup in achieving good precision both in natural warm-up/cooldown and controlled measurements are (i) the continuous DeltaT control across the sample by a chromel-AuFe(0.07%) thermocouple and (ii) the measurements of emf generated across the sample and the thermocouple using a nanovoltmeter and a scanner system. The versatile nature of the setup is further demonstrated by employing it in a magnetic field environment up to 140 kOe. The precision achieved using this system is highlighted for a few systems of current interest.

Do the grain boundaries of β-In2S3 thin films have a role in sub-band-gap photosensitivity to 632.8nm?

Highly photoconducting β-In2S3 thin films with conducting grain boundaries were obtained, using “chemical spray pyrolysis” technique. By varying the atomic ratio of the precursor solution used for spray pyrolysis, the photoconductivity of these films could be tailored. Conducting grain boundaries were found only for samples with a specific stoichiometry and these films exhibited photoresponse to intrinsic and extrinsic excitation wavelengths in the range of 325–532nm. Postdeposition vacuum annealing of these films enhanced the grain boundary conductivity, caused the films to exhibit persistent photoconductivity for both intrinsic and extrinsic excitations and extended the extrinsic photoresponse to wavelengths beyond 632.8nm. Photoresponse to excitation wavelength of 632.8nm was observed in films with and without conducting grain boundaries which proved that the extrinsic photoresponse to this wavelength was an effect associated with the defect chemistry of the β-In2S3.

Investigation of weak itinerant ferromagnetism and critical behavior of Y 2 Ni 7

The weak itinerant ferromagnetic behavior of Y

Thermally stimulated depolarization current studies of relaxation in L-asparagine monohydrate

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Low temperature thermal windowing (TW) thermally stimulated depolarization current (TSDC) setup

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Mapping of Magnetic Domains by MFM in Ni 2 MnGa

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Resonant dipolar relaxation in poly ( ε-caprolactone)—A thermally stimulated depolarization current study

is investigated through magnetic, transport, and calorimetric measurements. The low value of the saturation moment, large Rhodes-Wohlfarth ratio, large value of the linear term in heat capacity, and Fermi-liquid-like resistivity behavior with enhanced electron-electron scattering contribution establish firmly the weak itinerant ferromagetic nature of the sample. The critical exponents associated with the paramagnetic-to-ferromagnetic transition are also investigated from magnetization isotherms using modified Arrott plot, Kouvel-Fisher plot, and critical isotherm technique. The more accurate Kouvel-Fisher plot provides the critical exponents to be

Bioelectret state in aromatic amino acids: A Thermally Stimulated Depolarization Current study of phenylalanine, tyrosine and tryptophan

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Domain Structures across the Martensitic Transformation in Ni2+xMn1-xGa

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Effect of Molarity of Precursor Solution on Nanocrystalline Zinc Oxide Thin Films

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