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Recurring polyhedral motifs in the amorphous indium gallium zinc oxide network
Author(s) -
Divya,
Prasad Rajendra,
Deepak
Publication year - 2017
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201600471
Subject(s) - polyhedron , tetrahedron , octahedron , crystallography , indium , amorphous solid , gallium , zinc , coordination number , materials science , group (periodic table) , ionic bonding , crystal structure , chemistry , ion , geometry , mathematics , metallurgy , organic chemistry
The coordination polyhedra around the cations are the building blocks of ionic solids. For amorphous InGaZn oxide (a‐IGZO), these coordination polyhedra are identified to investigate properties that depend on short range interactions. Therefore, in this first principles based study, a large number (10) of samples of a‐IGZO were prepared by ab initio melt‐and‐quench molecular dynamics, so that several distinct samples of the amorphous landscape are obtained corresponding to local minima in energy. Based on a method of comparing bond angles between metal and oxygen atoms, the identified polyhedra were matched to the polyhedral motifs present in the related crystalline systems, such as, InGaZnO 4 , In 2 O 3 , Ga 2 O 3 , and ZnO. Consequently, we find, the a‐IGZO primarily consists of the following polyhedra: a tetrahedron from space group 199 and an octahedron from space group 206 of In 2 O 3 ; a tetrahedron from space group 12 and an octahedron from space group 167 of Ga 2 O 3 ; a tetrahedron from space group 186 of ZnO; zinc and gallium trigonal bipyramids from c‐IGZO; and one zinc fourfold, one zinc fivefold, and one indium fivefold coordination polyhedra that occur only in the amorphous phase. Thus, we were able to reduce the description of structure from 360 to 10 groups of polyhedra.