Deciphering phase evolution in complex metal oxide thin films via high-throughput materials synthesis and characterization

Ruoshui Li; Xuance Jiang; Chenyu Zhou; Mehmet Topsakal; Dmytro Nykypanchuk; Klaus Attenkofer; Dario J Stacchiola; Mark S Hybertsen; Eli Stavitski; Xiaohui Qu; Deyu Lu; Mingzhao Liu

doi:10.1088/1361-6528/acad09

Deciphering phase evolution in complex metal oxide thin films via high-throughput materials synthesis and characterization

Nanotechnology. 2023 Jan 6;34(12). doi: 10.1088/1361-6528/acad09.

Authors

Ruoshui Li^{1

2}, Xuance Jiang^{1

3}, Chenyu Zhou¹, Mehmet Topsakal¹, Dmytro Nykypanchuk¹, Klaus Attenkofer⁴, Dario J Stacchiola¹, Mark S Hybertsen¹, Eli Stavitski⁴, Xiaohui Qu¹, Deyu Lu¹, Mingzhao Liu¹

Affiliations

¹ Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, United States of America.
² Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, United States of America.
³ Department of Physics, Stony Brook University, Stony Brook, NY 11794, United States of America.
⁴ National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973, United States of America.

PMID: 36538812
DOI: 10.1088/1361-6528/acad09

Abstract

Discovery of structure-property relationships in thin film alloys of complex metal oxides enabled by high-throughput materials synthesis and characterization facilities is demonstrated here with a case-study. Thin films of binary transition metal oxides (Ti-Zn) are prepared by pulsed laser deposition with continuously varying Ti:Zn ratio, creating combinatorial samples for exploration of the properties of this material family. The atomic structure and electronic properties are probed by spatially resolved techniques including x-ray absorption near edge structures (XANES) and x-ray fluorescence (XRF) at the Ti and Zn K-edge, x-ray diffraction, and spectroscopic ellipsometry. The observed properties as a function of Ti:Zn ratio are resolved into mixtures of five distinguishable phases by deploying multivariate curve resolution analysis on the XANES spectral series, under constraints set by results from the other characterization techniques. First-principles computations based on density function theory connect the observed properties of each distinct phase with structural and spectral characteristics of crystalline polymorphs of Ti-Zn oxide. Continuous tuning of the optical absorption edge as a function of Ti:Zn ratio, including the unusual observation of negative optical bowing, exemplifies a functional property of the film correlated to the phase evolution.

Keywords: DFT computation; combinatorial thin film synthesis; high-thorough characterization; multivariate curve resolution; pulsed laser deposition; x-ray absorption spectroscopy.