Manipulating magnetoelectric energy landscape in multiferroics

• Published in: Nature communications Vol. 11; no. 1; p. 2836
• Main Authors: Huang, Yen-Lin, Nikonov, Dmitri, Addiego, Christopher, Chopdekar, Rajesh V., Prasad, Bhagwati, Zhang, Lei, Chatterjee, Jyotirmoy, Liu, Heng-Jui, Farhan, Alan, Chu, Ying-Hao, Yang, Mengmeng, Ramesh, Maya, Qiu, Zi Qiang, Huey, Bryan D., Lin, Chia-Ching, Gosavi, Tanay, Íñiguez, Jorge, Bokor, Jeffrey, Pan, Xiaoqing, Young, Ian, Martin, Lane W., Ramesh, Ramamoorthy
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.06.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 147/138; 147/3; 639/301/119; 639/301/357; Antiferromagnetism; Bismuth ferrite; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; condensed-matter physics; Coupling; Crystal structure; Engineering; Ferroelectricity; Ferromagnetism; Handedness; Humanities and Social Sciences; Laboratories; Materials science; multidisciplinary; Multiferroic materials; nanoscale materials; Phase transitions; Physical properties; Physics; Potential energy; Rare earth elements; Room temperature; Rotation; Science; Science (multidisciplinary); Spintronics; Thin films
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-16727-2

Magnetoelectric coupling at room temperature in multiferroic materials, such as BiFeO 3 , is one of the leading candidates to develop low-power spintronics and emerging memory technologies. Although extensive research activity has been devoted recently to exploring the physical properties, especially focusing on ferroelectricity and antiferromagnetism in chemically modified BiFeO 3 , a concrete understanding of the magnetoelectric coupling is yet to be fulfilled. We have discovered that La substitutions at the Bi-site lead to a progressive increase in the degeneracy of the potential energy landscape of the BiFeO 3 system exemplified by a rotation of the polar axis away from the 〈111〉 pc towards the 〈112〉 pc discretion. This is accompanied by corresponding rotation of the antiferromagnetic axis as well, thus maintaining the right-handed vectorial relationship between ferroelectric polarization, antiferromagnetic vector and the Dzyaloshinskii-Moriya vector. As a consequence, La-BiFeO 3 films exhibit a magnetoelectric coupling that is distinctly different from the undoped BiFeO 3 films. BiFeO 3 has a wide application but the impact of rare-earth substitution for the evolution of the coupling mechanism is unknown. Here, the authors reveal the correlation between ferroelectricity, antiferromagnetism, a weak ferromagnetic moment, and their switching pathways in La-substituted BiFeO 3 .