Crystal growth engineering and origin of the weak ferromagnetism in antiferromagnetic matrix of orthochromates from t- e orbital hybridization

Yinghao Zhu; Junchao Xia; Si Wu; Kaitong Sun; Yuewen Yang; Yanling Zhao; Hei Wun Kan; Yang Zhang; Ling Wang; Hui Wang; Jinghong Fang; Chaoyue Wang; Tong Wu; Yun Shi; Jianding Yu; Ruiqin Zhang; Hai-Feng Li

doi:10.1016/j.isci.2022.104111

Crystal growth engineering and origin of the weak ferromagnetism in antiferromagnetic matrix of orthochromates from t- e orbital hybridization

iScience. 2022 Mar 18;25(4):104111. doi: 10.1016/j.isci.2022.104111. eCollection 2022 Apr 15.

Authors

Yinghao Zhu^{1

2

3

4}, Junchao Xia^{1

4}, Si Wu^{1

4}, Kaitong Sun¹, Yuewen Yang², Yanling Zhao², Hei Wun Kan², Yang Zhang³, Ling Wang³, Hui Wang³, Jinghong Fang³, Chaoyue Wang³, Tong Wu³, Yun Shi³, Jianding Yu³, Ruiqin Zhang², Hai-Feng Li¹

Affiliations

¹ Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macao SAR 999078, China.
² Department of Physics, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China.
³ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
⁴ Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology, No. 1. Zhongziyuan Road, Dalang, DongGuan 523803, China.

Abstract

We report a combined experimental and theoretical study on intriguing magnetic properties of quasiferroelectric orthochromates. Large single crystals of the family of RECrO₃ (RE = Y, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) compounds were successfully grown. Neutron Laue study indicates a good quality of the obtained single crystals. Applied magnetic field and temperature dependent magnetization measurements reveal their intrinsic magnetic properties, especially the antiferromagnetic (AFM) transition temperatures. Density functional theory studies of the electronic structures were carried out using the Perdew-Burke-Ernzerhof functional plus Hubbard U method. Crystallographic information and magnetism were theoretically optimized systematically. When RE³⁺ cations vary from Y³⁺ and Eu³⁺ to Lu³⁺ ions, the calculated t-e orbital hybridization degree and Néel temperature behave similarly to the experimentally determined AFM transition temperature with variation in cationic radius. We found that the t-e hybridization is anisotropic, causing a magnetic anisotropy of Cr³⁺ sublattices. This was evaluated with the nearest-neighbor J ₁-J ₂ model. Our research provides a picture of the electronic structures during the t-e hybridization process while changing RE ions and sheds light on the nature of the weak ferromagnetism coexisting with predominated antiferromagnetism. The available large RECrO₃ single crystals build a platform for further studies of orthochromates.

Keywords: Condensed matter physics; Crystal engineering; Magnetism.