• R THANGAVEL

Articles written in Bulletin of Materials Science

• Theoretical investigation on the electronic and optical properties of BSTS compounds with SOC and TB_mBJ potentials

In this study, we report on electronic and optical properties of the bulk and primitive structure of A$_2$B$_3$(A = Bi or Sb and B = Se or Te) compounds using FP-LAPW method within density functional theory. The potentials for exchange and correlation is treated within generalized gradient approximation-Perdew Burke Ernzerhof and Tran-Blahamodified Becke–Johnson (TB_mBJ). The inclusion of spin-orbit coupling approximation is used to calculate electronicstructures and optical properties by determining the complex dielectric function, from which the other parameters arederived. The obtained results are in good agreement with the experimental results. Also, Sb$_2$Te$_3$ compounds have beenfound to possess maximum value of absorption and reflection among all the studied compounds. For all the compounds, astrong absorption coefficient ($\alpha$) exists between the energy range 0 and 5 eV, and is greater than 10$^5$ cm$^{–1}$, which makesthem suitable for optoelectronic applications.

• Investigation on the structural and magnetic properties of M$_x$Bi$_{2–x}$Te$_3$ (M = Gd, Fe, Cr) (x = 0, 1) using colloidal hot-injection method

Gadolinium-doped bismuth telluride (GBT), ferric-doped bismuth telluride (FBT) and chromium-doped bismuth telluride (CBT) nanocrystals have been synthesized using colloidal hot-injection method with same doping ratio. Field-oriented uniaxial anisotropic ferromagnetic properties for all the samples were analysed from the squareness ratio ($M_r$/$M_s$), $K_1$ (magnetocrystalline anisotropic constant), $K_1$$^v$ (shape anisotropic constant), $K_{eff}$ (effective anisotropy constant) and magnetic energy using vibration sample magnetometer. The magneto-impedance (MI) spectral ratio (${\Delta}$Z/$Z_0$)% has been influenced by rotational magnetization, as well as domain wall motion with respect to applied magnetic field. The results have proven that the GBT thin film sample exhibits the maximum MI effect. Our results may shed light on the simple method of synthesis and development of the effective MI materials based on rare-earth/transition-doped bismuth telluride for the realization of magnetic sensor applications in future.

• # Bulletin of Materials Science

Volume 45, 2022
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