Synthesis and Characterization of Bulk Nd1-xSrxNiO2 and Nd1-xSrxNiO3

Published

August 21, 2020

Author(s)

Bi-Xia Wang, Hong Zheng, E. Krivyakina, Omar Chmaissem, Pietro Papa Lopes, Jeffrey W. Lynn, Leighanne C. Gallington, Y. Ren, S. Rosenkranz, J. F. Mitchell, D. Phelan

Abstract

The recent reports of superconductivity in Nd_1-xSr_xNiO₂/SrTiO₃ heterostructures have reinvigorated interest in potential superconductivity of low-valence nickelates. Synthesis of Ni¹⁺ -containing compounds is notoriously difficult. In the current work, a combined sol-gel combustion and high-pressure annealing technique was employed to prepare polycrystalline perovskite Nd^1-x^Sr_xNiO₃ (x = 0, 0.1 and 0.2). Metal nitrates and metal acetates were used as starting materials, and the latter were found to be superior to the former in terms of safety and reactivity. The Nd_1-xSr_xNiO₃ compounds were subsequently reduced to Nd_1-xSr_xNiO₂ using calcium hydride in a sealed, evacuated quartz tube. To understand the synthesis pathway, the evolution from NdNiO₃ to NdNiO₂ was monitored using in-situ synchrotron X-ray diffraction during the reduction process. Electrical transport properties were consistent with an insulatormetal transition occurring between x = 0 and 0.1 for Nd_1-xSr_xNiO₃. Superconductivity was not observed in our bulk samples of Nd_1-xSr_xNiO₂. Neutron diffraction experiments at 3 K and 300 K were performed on Nd_0.9Sr_0.1NiO₂, in which no magnetic Bragg reflections were observed, and the results of structural Rietveld refinement are provided.

Citation

Physical Review Materials

Volume

4

Issue

8

Pub Type

Journals

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Keywords

Nickelates, Superconductivity, Neutron Diffraction, Crystal Structure, Synthesis, sol-gel combustion, electrical transport

Citation

Wang, B. , Zheng, H. , Krivyakina, E. , Chmaissem, O. , Lopes, P. , Lynn, J. , Gallington, L. , Ren, Y. , Rosenkranz, S. , Mitchell, J. and Phelan, D. (2020), Synthesis and Characterization of Bulk Nd_1-xSr_xNiO₂ and Nd_1-xSr_xNiO₃, Physical Review Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930647 (Accessed April 23, 2024)