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Title: Structural distortion and band gap opening of hard MnB{sub 4} in comparison with CrB{sub 4} and FeB{sub 4}

MnB{sub 4} was newly synthesized to crystallize in a monoclinic P2{sub 1}/c structure, different from previous experimental and theoretical reports. Here, based on first-principles calculations, we perform a comparative study of geometric and energetic features, mechanical behaviors, electronic property and chemical bonding of the experimentally identified monoclinic MnB{sub 4}, as well as orthorhombic CrB{sub 4} and FeB{sub 4}. The results demonstrate that the presence of distorted rhomboidal-B{sub 4} units and one-dimensional Mn chains in the monoclinic MnB{sub 4} breaks the structural symmetry and lowers the total energy in comparison to the orthorhombic phase. The opening of band gap in MnB{sub 4} is induced by Peierls-paired Mn atoms, differing from the metallic behaviors of recently studied tetraborides. Specifically, the preservations of covalent bonding in distorted boron-rhomboids in MnB{sub 4} explain the relatively higher incompressibility and hardness. - Graphical abstract: P2{sub 1}/c-type structure for MnB{sub 4} characterizes rhomboid-B{sub 4} units and alternately short and long Mn–Mn chains. - Highlights: • The novel P2{sub 1}/c-type MnB{sub 4} compound is studied by first-principles calculations. • P2{sub 1}/c-type MnB{sub 4} has lower total energy and relatively higher stability. • An energy gap opening is found for P2{sub 1}/c-type MnB{sub 4} induced by Mn atom pairs.more » • P2{sub 1}/c-type MnB{sub 4} exhibits excellent mechanical properties. • The mechanical properties of TcB{sub 4} and ReB{sub 4} in P2{sub 1}/c structure are also studied.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ; ;  [1] ;  [1] ;  [1]
  1. Key Laboratory of Metastable Materials Science and Technology, College of Material Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)
  2. Research Center for Solid State Physics and Materials, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009 (China)
  3. Key Laboratory of Applied Chemistry, Yanshan University, Hebei Qinhuangdao 066004 (China)
  4. Laboratory of Crystallography, University of Bayreuth, 95440 Bayreuth (Germany)
Publication Date:
OSTI Identifier:
22334235
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 213; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATOMS; ENERGY GAP; HARDNESS; IRON BORIDES; MANGANESE BORIDES; MONOCLINIC LATTICES; ORTHORHOMBIC LATTICES