Strain control of phase transition and magnetic property in multiferroic BiFeO3 thin films

THIN SOLID FILMS

卷:695

Article

Zheng, Wanchao¹  Zheng, Dongxing¹  Li, Dong¹  Li, Peng²  Zhang, Linxing³  Gong, Junlu¹  Pang, Xin¹  Jin, Chao¹  Zhang, Xixiang²  Bai, Haili¹ 

[1] Tianjin Univ, Sch Sci, Tianjin Key Lab Low Dimens Mat Phys & Proc Techno, Tianjin 300350, Peoples R China

[2] KAUST, Phys Sci & Engn PSE Div, Thuwal 239556900, Saudi Arabia

[3] Univ Sci & Technol Beijing, Inst Adv Mat & Technol, Beijing 100083, Peoples R China

关键词: Strain effect;    Spin canting;    Orbital reconstruction;    Magnetic moment;    Bismuth ferrite;   

DOI  :  10.1016/j.tsf.2019.137741

来源: Elsevier

【 摘 要 】

BiFeO3 (BFO), a room-temperature antiferromagnetic-ferroelectric multiferroic, is widely researched due to its potential applications for electric-field control of the magnetism. In this work, the strain control of the phase transition and magnetic properties in the BFO/LaAlO3 heterostructures were investigated. The O K edge polarization-dependent X-ray absorption spectroscopy (XAS) spectra show that the Fe 3d level splits into five levels, which proves that the FeO(5)( )pyramid is asymmetric in the highly strained tetragonal-like BFO. The spin canting induced by the asymmetric structure leads to the magnetic moment. Thus, an obvious magnetic signal in the 17-nm-thick BFO thin films was observed by the Quantum Design magnetic property measurement system. With the increase of the BFO film thickness, the clamping effect induced by the substrate becomes weak, further leading to the BFO phase transition. The O K edge polarization-dependent XAS spectra demonstrate that the orbital reconstruction exists at the mixed BFO phase boundaries. Since the orbital reconstructions can induce the strong magnetic coupling, the magnetic order of the different BFO phases will be coupled with each other. It causes a variation of the magnetic property at the phase boundaries or in the BFO phases.

【 授权许可】

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