Chemical State Analysis Assisted Combinatorial Exploration of New Phase Spaces: Application to Ternary Zn-M-N Nitrides and Synthesis of Wurtzite Zn₂TaN₃.

When and Where

Nov 28, 2023
8:00pm - 10:00pm

Hynes, Level 1, Hall A

Presenter

Siarhei Zhuk

Alexander Wieczorek

Amit Sharma

Jyotish Patidar

Kerstin Thorwarth

Johann Michler

Sebastian Siol

Co-Author(s)

Sebastian Siol¹,Siarhei Zhuk¹,Alexander Wieczorek¹,Amit Sharma²,Jyotish Patidar¹,Kerstin Thorwarth¹,Johann Michler²

Empa-Swiss Federal Institute of Materials Science and Technology¹,Empa–Swiss Federal Laboratories for Materials Science and Technology²

Abstract

Sebastian Siol¹,Siarhei Zhuk¹,Alexander Wieczorek¹,Amit Sharma²,Jyotish Patidar¹,Kerstin Thorwarth¹,Johann Michler²

Empa-Swiss Federal Institute of Materials Science and Technology¹,Empa–Swiss Federal Laboratories for Materials Science and Technology²

The experimental realization of predicted functional materials is a key challenges in the development of new technologies.[1] Combinatorial high-throughput approaches using reactive sputtering and automated analysis are commonly employed to screen unexplored phase spaces.[1,2] Especially, when synthesizing new materials in complex phase spaces results from a conventional structural phase screening can be ambiguous. In this presentation, we show how chemical state analysis based on X-ray photoelectron spectroscopy can complement conventional high-throughput workflows. Specifically, we highlight how studies based on the Auger parameter are ideally suited to probe the local chemical state and coordination in insulating or semiconducting materials. Firstly, the Auger parameter is insensitive to charging and erroneous calibration of the instrument.[3,4] Secondly, the analysis typically does not require multi-component peak fitting, which facilitates high-throughput workflows.[4] As a proof of concept, we perform a combinatorial screening of the Zn-Ta-N phase space with the aim to synthesize the novel semiconductor Zn2TaN3. While the results of the XRD phase screening are inconclusive, including chemical state analysis mapping in our workflow allows us to see a very clear discontinuity in the evolution of the Ta Auger parameter. This is indicative of a change in the Ta oxidation state and coordination and consequently confirms the formation of the phase of interest. In additional experiments, we then isolate the material and perform a detailed characterization confirming the formation of single phase WZ-Zn2TaN3.[5] Besides the formation of the new ternary nitride, we map the functional properties of ZnxTa1−xN and report previously unreported clean chemical state analysis for Zn3N2, TaN and Zn2TaN3. Overall, the results of this study showcase common challenges in high-throughput materials screening and highlight the merit of employing characterization techniques sensitive towards changes in the materials' short-range order and chemical state. The workflows and concepts described in this presentation are applicable to many different energy materials and can be applied using standard XPS equipment. [1] W. Sun et al., Nature Materials, 2019, 18, 732–739 [2] S. Zhuk, A. Kistanov, S. Boehme, N. Ott, F. La Mattina, M. Stiefel, M. V. Kovalenko, S. Siol, Chem. Mater. 2021, 33, 23, 9306–9316 [3] A. Wieczorek, H. Lai, J. Pious, F. Fu, S. Siol, Adv. Mater. Interfaces 2023, 10, 2201828. [4] S. Zhuk, S. Siol, Appl. Surf. Sci. 2022, 601, 154172. [5] S. Zhuk, A. Wieczorek, A. Sharma, J. Patidar, K. Thorwarth, J. Michler, S. Siol, under review, 2023. (arXiv:2305.19875)