Evolutionary Algorithm-Based Crystal Structure Prediction of CuxZnyOz Ternary Oxides

Abstract

Binary zinc(II) oxide (ZnO) and copper(II) oxide (CuO) are used in a number of applications, including optoelectronic and semiconductor applications. However, no crystal structures have been reported for ternary Cu-Zn-O oxides. In that context, we investigated the structural characteristics and thermodynamics of CuxZnyOz ternary oxides to map their experimental feasibility. We combined evolutionary crystal structure prediction and quantum chemical methods to investigate potential CuxZnyOz ternary oxides. The USPEX algorithm and density functional theory were used to screen over 4000 crystal structures with different stoichiometries. When comparing compositions with non-magnetic CuI ions, magnetic CuII ions, and mixed CuI-CuII compositions, the magnetic Cu2Zn2O4 system is thermodynamically the most favorable. At ambient pressures, the thermodynamically most favorable ternary crystal structure is still 2.8 kJ/mol per atom higher in Gibbs free energy compared to experimentally known binary phases. The results suggest that thermodynamics of the hypothetical CuxZnyOz ternary oxides should also be evaluated at high pressures. The predicted ternary materials are indirect band gap semiconductors.

Chemical Bonding and Crystal Structure Schemes in Atomic/Molecular Layer Deposited Fe-Terephthalate Thin Films

“…In the evolutionary searches, interfaces with two quantum chemical codes, CRYSTAL17/23 and DFTB (version 22.2), were used. USPEX combined with CRYSTAL has previously been used to investigate, for example, the ground state structures of different known and unknown magnetic d -metal oxides, , novel synthesized fluorides, as well as novel dilithium 2-aminoterephthalate material obtained through ALD/MLD . Evolutionary structure search was complemented with the investigation of known d -metal MOF structures: Sc­(III) 2 -BDC 3 , Cu­(II)-BDC MOF-2, and Co­(II)-BDC MOF-71 …”