DSpace Community: Assistant Professor, PUC Campus, Aizawl

Enhanced H2 Storage Capacity of Bilayer Hexagonal Boron Nitride (h-BN) Incorporating van der Waals Interaction under an Applied External Electric Field

Thu, 12 Aug 2021 00:00:00 GMT

Title: Enhanced H2 Storage Capacity of Bilayer Hexagonal Boron Nitride (h-BN) Incorporating van der Waals Interaction under an Applied External Electric Field Authors: Rai, Dibya Prakash Abstract: Lightweight two-dimensional materials are being studied for hydrogen storage applications due to their large surface area. The characteristics of hydrogen adsorption on the h-BN bilayer under the applied electric field were investigated. The overall storage capacity of the bilayer is 6.7 wt % from our theoretical calculation with Eads of 0.223 eV/H2. The desorption temperature to remove the adsorbed H2 molecules from the surface of the h-BN bilayer system in the absence of an external electric field is found to be ∼176 K. With the introduction of an external electric field, the Eads lies in the range of 0.223−0.846 eV/H2 and the desorption temperature is from 176 to 668 K. Our results show that the external electric field enhances the average adsorption energy as well as the desorption temperature and thus makes the h-BN bilayer a promising candidate for hydrogen storage.

Hydrogen Storage in Bilayer Hexagonal Boron Nitride: A FirstPrinciples Study

Wed, 20 Oct 2021 00:00:00 GMT

Title: Hydrogen Storage in Bilayer Hexagonal Boron Nitride: A FirstPrinciples Study Authors: Rai, Dibya Prakash Abstract: Using first-principles calculations, we report on the structural and electronic properties of bilayer hexagonal boron nitride (h-BN), incorporating hydrogen (H2) molecules inside the cavity for potential H2-storage applications. Decrease in binding energies and desorption temperatures with an accompanying increase in the weight percentage (upto 4%) by increasing the H2 molecular concentration hints at the potential applicability of this study. Moreover, we highlight the role of different density functionals in understanding the decreasing energy gaps and effective carrier masses and the underlying phenomenon for molecular adsorption. Furthermore, energy barriers involving H2 diffusion across minimum-energy sites are also discussed. Our findings provide significant insights into the potential of using bilayer h-BN in hydrogen-based energy-storage applications.

Study of energy bands and magnetic properties of Co2CrSi Heusler alloy

Sat, 01 Oct 2011 00:00:00 GMT

Title: Study of energy bands and magnetic properties of Co2CrSi Heusler alloy Authors: Rai, Dibya Prakash Abstract: The electronic and magnetic properties of Co2CrSi is calculated by using full-potential linearized augmented plane wave (FP–LAPW) method based on density functional theory (DFT). Density of states (DOS), magnetic moment and band structures of the system are presented. For the exchange and correlation energy, local spin density approximation (LSDA+U) with the inclusion of Hubbard potential U is used. Our calculation shows indirect bandgap of 0·91 eV in the minority channel of DOS. This is supported by band structures and hence favoured the half metallic ferromagnetic (HMF) nature of the system. The effective magnetic moment of 4·006 μB also supported our conclusion with a near integral value. The DOS of Co and Cr were found to hybridize and was also responsible for the ferromagnetic nature of the system.

Study of the Fe2CoAl heusler alloy films growth on the R-plane sapphire substrate by scanning probe microscopy

Tue, 09 Jul 2019 00:00:00 GMT

Title: Study of the Fe2CoAl heusler alloy films growth on the R-plane sapphire substrate by scanning probe microscopy Authors: Rai, Dibya Prakash Abstract: The grown films of FCA Heusler alloy on the R-plane sapphire with and without the W (001) seed layer were studied using scanning atomic and magnetic force microscopies, supplemented with the results of micromagnetic calculations and measurements of film magnetoresistance. Nonmonotonic dependences of the films’ morphological and magnetic properties on their growth temperature caused, as assumed, by the formation of some disordered phase at temperatures of 50