Nanoscale structural analysis of Pb(Mg1/3Nb2/3)O3

Yasuhiro Yoneda; Hiroki Taniguchi; Yuji Noguchi

doi:10.1088/1361-648X/abb866

Nanoscale structural analysis of Pb(Mg_1/3Nb_2/3)O₃

J Phys Condens Matter. 2020 Oct 16;33(3). doi: 10.1088/1361-648X/abb866.

Authors

Yasuhiro Yoneda¹, Hiroki Taniguchi², Yuji Noguchi³

Affiliations

¹ Reaction Dynamics Research Division, Japan Atomic Energy Agency (JAEA), Sayo, Hyogo 679-5148, Japan.
² Department of Physics, Nagoya University, Furo-cho, Nagoya 464-8601, Japan.
³ Department of Applied Chemistry, School of Engineering, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan.

PMID: 32927450
DOI: 10.1088/1361-648X/abb866

Abstract

The determination of local atomic structure at nanoscale for inhomogeneous systems is challenging. The local arrangement of atoms needs to be studied to understand the local or short-range order structures for disordered materials with a lack of long-range order periodicity. Pair distribution function (PDF) analysis is a technique, that is used to study the short-range order structure of materials: this technique is based on the evaluation of local atomic arrangement using synchrotron and neutron sources. An attempt was made to determine the local arrangement at 20 nm-scale for a typical relaxor ferroelectric material, Pb(Mg_1/3Nb_2/3)O₃(PMN). The PDF technique was employed owing to the limited structural coherence in this disordered material. It was determined that there are three types of structures depending on the distance. A glass-like network structure was observed as a short-range order structure owing to the large off-center shift of lead atoms. With an increase in distance, the structure of PMN changed from rhombohedral to cubic. Using the above-mentioned approach, we elucidated the process of local structure averaging.

Keywords: local structure; pair distribution function; relaxor ferroelectrics; synchrotron x-ray powder diffraction.