• S MUKHERJEE

Articles written in Bulletin of Materials Science

• Preparation of glass-nickel microcomposites byin situ reduction via sol-gel route

Gel has been prepared with nickel chloride and glucose in the starting solution followed by heat treatment at higher temperature, where glucose decomposes to carbon and water vapour, which in turn react to form hydrogenin situ to reduce nickel chloride to metallic nickel. The presence and distribution of nickel granules in the microcomposite, has been established by transmission electron microscopy, selected area diffraction and electron paramagnetic resonance analysis.

• Isothermalin situ reduction kinetic analysis of NiCl2-containing gel

Isothermalin situ reduction kinetic study of NiCl2-containing gel was carried out. The detailed statistical as well as reduced time analysis show that contracting geometry and nucleation and growth type of mixed mechanisms are operative. The activation energy for reduction is in the range 158–193 kJ/mol. Thermal analysis on NiCl2-containing gel was carried out in the temperature range 800°C to 900°C.

• Preparation of silica monolith via sol-gel route

The present investigation deals with the synthesis of monolithic NiCl2-silica gels obtained by hydrolysis and polycondensation of tetraethoxy silanes. This sol to gel formation can mainly be controlled by adjusting some variables e.g. acid content of the solution, ageing and leaching times. A minimum acid content was found necessary to prepare uncracked gel while ageing and leaching times were found to be not that sensitive for the formation of uncracked gels.

• De-stabilization of charge-order state through in-homogeneity in random ionic distribution in the particles of polycrystalline Eu$_{0.2}$La$_{0.3}$Sr$_{0.2}$Ca$_{0.3}$MnO$_3$ sample

In this study the perovskite manganite Eu$_{0.2}$La$_{0.3}$Sr$_{0.2}$Ca$_{0.3}$MnO$_{3}$ batch integrated sample is studied, with special modification done to introduce localized structural strain without micro-level (grains) modification. This consequence successfully generates opposite nature of high orthorhombic strain along b-axis in these samples, although the general structure is same for both with $Pnma$ space group. The sharp magnetic transitions (both Curie temperature and charge-ordertransition) are reported to be mixed in presence of random ionic distribution in its structure. The diffused insulator-metal behaviour, de-stabilization of magnetic state and phase transitions associated with inherent anisotropic strain is discussed and is explained based on chemical disorder-induced structural strain in the present system.

• Bulletin of Materials Science

Volume 43, 2020
All articles
Continuous Article Publishing mode

• Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020

Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020

• Editorial Note on Continuous Article Publication

Posted on July 25, 2019

Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.