Research of structure and magnetic properties of thick BaFe₁₂O₁₉ films obtained by slip casting

Anisotropic thick films of hexagonal barium ferrite BaFe₁₂O₁₉ are used in the design and manufacture of microstrip microwave electronics devices, spinwave electronics devices and magnonics. The aim of the work is to study the crystal structure and magnetic properties of BaFe₁₂O₁₉ films of different thicknesses. The films were obtained by the method of slip casting. The starting material is ferritized barium hexaferrite powder synthesized using standard ceramic technology. Polyvinyl butyral was used as a film-forming agent, ethyl alcohol, butyl acetate and dibutyl phthalate were used as solvents. The ratio of BaFe₁₂O₁₉ powder to solvent film-forming agent was 70/30, and the thickness of the obtained films after sintering was 73, 340, and 770 μm. X-ray phase analysis of the samples was performed using an automated X-ray diffractometer DRON-4, the magnetic hysteresis loops of the study objects were recorded at room temperature. It is established that the main phase of the films is barium hexaferrite (crystal lattice parameters: a = 5.88 Å, c = 23.19 Å). The impurity found on the diffractograms probably refers to the film-forming agent and solvent. It is shown that the coercive force of the synthesized films is ~3 kOe, the residual specific magnetization is 20 – 26 emu/g, and the degree of magnetic texture is in the range of 10.98 – 15.7, which indicates the anisotropy of the samples. The results obtained can be used in the manufacture and improvement of devices for magnetoelectronics, microwave microelectronics, as well as spinwave electronics and magnonics.

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