• J KUMAR

      Articles written in Bulletin of Materials Science

    • Photoinduced fabrication of complex surface relief structures on azobenzene functionalized polymers

      J Kumar L Li Nirmal K Viswanathan S Bian S Balasubramanian D Y Kim S K Tripathy

      More Details Abstract Fulltext PDF

      Light induced fabrication of complex surface relief structures on azobenzene functionalized polymers is reported. Large class of side chain and main chain polymers can be utilized to record these relief structures. The recording and erasure process are strongly dependent on the polarization. Possible transport mechanism of polymer chains well below the glass transition temperature due to photoinduced effect is discussed.

    • Studies on structural and magnetic properties of NdFeO$_3$ single crystals grown by optical floating zone technique

      T SHALINI P VIJAYAKUMAR J KUMAR

      More Details Abstract Fulltext PDF

      NdFeO$_3$ single crystals have been grown by optical floating-zone technique using Nd$_2$O$_3$ and Fe$_2$O$_3$ as the source by solid-state reaction method. The crystalline structure of NdFeO$_3$ belongs to orthorhombic symmetry and the presence of a distorted perovskite structure was confirmed by powder X-ray diffraction (XRD) analysis. From the XRDresults, it is visualized that the lattice expansion has been observed in the unit cell parameters which may appear due to interstitial defects in the NdFeO$_3$ matrix. The deficiency of oxygen atoms and the presence of excess Fe ions in NdFeO$_3$ have been confirmed with EDX spectra. The spin-reorientation region ($T=120$ K) exhibits lower coercive field and the hysteresis loops depict enhanced magnetization ($M_{\rm s}$ and $M_{\rm r}$) values of NdFeO$_3$ single crystal. Presence of compensation temperature point at $T_{\rm comp} = 7.5$ K denotes the anti-parallel alignment of rare-earth ions with Fe magnetic moments. At high temperatures, Fe$^{3+}$ magnetic moments show strong antiferromagnetic interactions ensuing in Neel temperature ($T_{\rm N}$)at 690 K.

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    • 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

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