Theoretical Prediction and Synthesis of a Family of Atomic Laminate Metal Borides with In-Plane Chemical Ordering.

ABSTRACT: All atomically laminated MAB phases (M = transition metal, A = A-group element, and B = boron) exhibit orthorhombic or tetragonal symmetry, with the only exception being hexagonal Ti₂InB₂. Inspired by the recent discovery of chemically ordered hexagonal carbides, i-MAX phases, we perform an extensive first-principles study to explore chemical ordering upon metal alloying of M₂AlB₂ (M from groups 3 to 9) in orthorhombic and hexagonal symmetry. Fifteen stable novel phases with in-plane chemical ordering are identified, coined i-MAB, along with 16 disordered stable alloys. The predictions are verified through the powder synthesis of Mo_4/3Y_2/3AlB₂ and Mo_4/3Sc_2/3AlB₂ of space group R

SUBMITTER: Dahlqvist M 

PROVIDER: S-EPMC7596753 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature