Anisotropic magnetoresistance across Verwey transition in charge ordered Fe3O4 epitaxial films
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
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AbstractThe anisotropic magnetoresistance (AMR) near the Verwey temperature (T-V) is investigated in charge ordered Fe3O4 epitaxial films. When the temperature continuously decreases below T-V, the symmetry of AMR in Fe3O4(100) film evolves from twofold to fourfold at a magnetic field of 50 kOe, where the magnetic field is parallel to the film surface, whereas AMR in Fe3O4(111) film maintains twofold symmetry. By analyzing AMR below T-V, it is found that the Verwey transition contains two steps, including a fast charge ordering process and a continuous formation process of trimeron, which is comfirmed by the temperature-dependent Raman spectra. Just below T-V, the twofold AMR in Fe3O4(100) film originates from uniaxial magnetic anisotropy. The fourfold AMR at a lower temperature can be ascribed to the in-plane trimerons. By comparing the AMR in the films with two orientations, it is found that the trimeron shows a smaller resistivity in a parallel magnetic field. The field-dependent AMR results show that the trimeron-sensitive field has a minimum threshold of about 2 kOe.
CitationLiu X, Mi W, Zhang Q, Zhang X (2017) Anisotropic magnetoresistance across Verwey transition in charge ordered Fe3O4 epitaxial films. Physical Review B 96. Available: http://dx.doi.org/10.1103/PhysRevB.96.214434.
SponsorsThis work is supported by the National Natural Science Foundation of China (Grants No. 51671142 and No. U1632152) and the Key Project of the Natural Science Foundation of Tianjin (Grant No. 16JCZDJC37300).
PublisherAmerican Physical Society (APS)
JournalPhysical Review B