Local structure of the MgxNixCoxCuxZnxO(x=0.2) entropy‐stabilized oxide: An EXAFS study

• DOI: 10.1111/jace.14756
• Publication Date: 2017-04-10T07:32:42Z
• Authors: Christina M. Rost; Zsolt Rak; Donald W. Brenner; Jon‐Paul Maria
• Keywords: Coordination number

Abstract Entropy‐stabilized oxides (ESOs) provide an alternative route to novel materials discovery and synthesis. It is, however, a challenge demonstrate that the constituent elements in entropy‐stabilized crystal are homogeneously randomly dispersed among particular sublattice, resulting true solid solution with no evidence of local order or clustering. In this work, we present application analysis extended X‐ray absorption fine structure (EXAFS) on prototype ESO composition Mg x Ni Co Cu Zn O ( =0.2). so doing, can quantify atomic element‐by‐element basis. We conclude bond lengths between metal oxygen vary around each absorbing cation, notable distortion Cu–O polyhedra. By second near neighbor (i.e., cation‐cation pair), interatomic distances uniform extent collected data resolve. Crystal models best fit experimental scattering include cations distributed FCC sublattice minimal positional disorder, interleaved anion ions displaced from ideal locations accommodate distortions cation Density functional theory calculations system yield significant broadening distribution for compared all peaks, showing consistency conclusion rock salt occurs primarily through disorder sublattice.