Understanding Antiferromagnetic Coupling in Lead-Free Halide Double Perovskite Semiconductors

Kunpot Mopoung; Weihua Ning; Muyi Zhang; Fuxiang Ji; Kingshuk Mukhuti; Hans Engelkamp; Peter C M Christianen; Utkarsh Singh; Johan Klarbring; Sergei I Simak; Igor A Abrikosov; Feng Gao; Irina A Buyanova; Weimin M Chen; Yuttapoom Puttisong

doi:10.1021/acs.jpcc.3c08129

Understanding Antiferromagnetic Coupling in Lead-Free Halide Double Perovskite Semiconductors

J Phys Chem C Nanomater Interfaces. 2024 Mar 14;128(12):5313-5320. doi: 10.1021/acs.jpcc.3c08129. eCollection 2024 Mar 28.

Authors

Affiliations

¹ Department of Physics (IFM), Linköping University, Linköping 583 30, Sweden.
² Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, P.R. China.
³ High Field Magnet Laboratory (HFML - EMFL), Radboud University, Toernooiveld 7, Nijmegen 6525 ED, The Netherlands.
⁴ Department of Physics and Astronomy, Uppsala University, Uppsala SE-75120, Sweden.

Abstract

Solution-processable semiconductors with antiferromagnetic (AFM) order are attractive for future spintronics and information storage technology. Halide perovskites containing magnetic ions have emerged as multifunctional materials, demonstrating a cross-link between structural, optical, electrical, and magnetic properties. However, stable optoelectronic halide perovskites that are antiferromagnetic remain sparse, and the critical design rules to optimize magnetic coupling still must be developed. Here, we combine the complementary magnetometry and electron-spin-resonance experiments, together with first-principles calculations to study the antiferromagnetic coupling in stable Cs₂(Ag:Na)FeCl₆ bulk semiconductor alloys grown by the hydrothermal method. We show the importance of nonmagnetic monovalence ions at the B^I site (Na/Ag) in facilitating the superexchange interaction via orbital hybridization, offering the tunability of the Curie-Weiss parameters between -27 and -210 K, with a potential to promote magnetic frustration via alloying the nonmagnetic B^I site (Ag:Na ratio). Combining our experimental evidence with first-principles calculations, we draw a cohesive picture of the material design for B-site-ordered antiferromagnetic halide double perovskites.