Temperature- and Magnetic Field–Induced Magnetization Reversal in Aurivillius Bi5Ti3FeO15 Ceramics by Co Doping

The Bi5Ti3(Fe1−xCox)O15 (x = 0, 0.4, 0.5, 0.6, 0.7) ceramics synthesized by solid state reaction are investigated. The microstructures are Aurivillius phase with perovskite layered structure, which were analyzed by X-ray diffraction and Raman spectroscopy test. The temperature-dependent magnetization was systematically investigated for all samples with different Co doping ratios. The magnetization reversal effects were found in both ZFC and FC curves with one or two compensation temperature. And the compensate temperatures change with different x. The temperature-induced magnetization reversal may attribute to the competition between the super-exchange interaction of Fe3+-O-Fe3+ and Co3+-O-Co3+, the DM interaction of Fe3+-O-Co3+ chains, and the magneto-crystalline anisotropy. This competition can be affected by the contents of Fe ions to Co ions. The study of multiferroic material Bi5Ti3(Fe1−xCox)O15 ceramics with magnetization reversal effects has important significance in the Information Security Engineering, for the switch effect with different magnetizations and temperatures.