Multiferroic and in-plane magnetoelectric coupling properties of BiFeO₃ nano-films with substitution of rare earth ions La³⁺ and Nd³⁺

郭凯鑫¹，张荣芬¹，何腾鹏¹，孔汉东²，邓朝勇¹

1. Key Laboratory of Electronic Composites of Guizhou Province, College of Big Data and Information Engineering, Guizhou University2. Yangming Collage, Guizhou University

摘 要：Single-phase multiferroic BiFeO₃ and Bi_0.9（La/Nd）_0.1FeO₃(doped with rare earth ions La³⁺ and Nd³⁺) films grown on（111）-Pt/Ti/SiO₂/Si substrate were prepared via sol-gel method and a subsequent rapid thermal process. The phase composition, microstructure, ferroelectric, dielectric, ferromagnetic properties were investigated, and meanwhile, the in-plane magnetoelectric（ME） coupling effects of the films were reported and studied for the first time in this work. Structural characterization by X-ray diffraction and scanning electron microscopy showed that both BiFeO₃ and Bi_0.9（La/Nd）_0.1FeO₃ exhabited a rhombohedral structure with（111） preferred orientation. The results of the physical properties indicated that the introduction of rare earth ions improved significantly the polarization, magnetization and dielectric properties than the undoped BiFeO₃ crystals, and it enhanced effectively the in-plane ME coupling(the ME coupling coefficient αE increased from 0.13 in the pure BiFeO₃ to 0.21 in Bi_0.9La_0.1FeO₃ and 0.34 V/（Oe·cm） in Bi_0.9Nd_0.1FeO₃). The mechanism of these phenomena was investigated systematically.

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