Pressure Induced Structural Phase Transition, Metallization and Superconductivity in RbBr
Copyright (c) 2018 Orbital: The Electronic Journal of Chemistry
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
The structural phase transition, metallization and superconductivity of the simple alkali bromide, Rubidium bromide (RbBr) is investigated through their band structures. Under high pressure RbBr undergoes a structural phase transition from the NaCl structure (B1) to the CsCl structure (B2). The band structure, density of states (DOS) and total energy are computed as a function of volume for both B1 and B2 phases using the full potential linear muffin-tin orbital (FP-LMTO) method. The ground state properties and band gap values are compared with the experimental results. The pressure corresponding to structural phase transition from NaCl structure (B1) to the CsCl structure (B2) is 0.028 Mbar in RbBr. The metallization pressure PM is 1.172 Mbar. The superconducting transition temperatures (Tc) of RbBr is obtained as a function of pressure for both NaCl and CsCl structures. The highest Tc estimated is 2.151 K and the corresponding pressure is 4 Mbar in the NaCl structure and 0.819 K in the CsCl structure. It is also confirmed that the metallization, structural phase transition and onset of superconductivity do not occur simultaneously in ionic compounds.