Ferromagnetic/ferroelectric composites and microwave properties of its metamaterial structure

Abstract

A series of YIG/BST ferromagnetic/ferroelectric composites were prepared by solid-state reaction using yttrium iron garnet (Y3Fe5O12) and barium titanate (Ba0.5Sr0.5TiO3). The phase and microstructure of the composites were investigated by XRD and SEM, and the dielectric and magnetic property were studied in detail. The results show that the ferroelectric phase and ferromagnetic phase exist independently when the composite is sintered at a certain temperature; (1-x)YIG-xBST (x=0.1, 0.2, 0.3, 0.4, 0.5) composites possess great dielectric properties: at room temperature, with increasing frequency (102-106Hz), the dielectric constant of each component composite and the dielectric loss decreases gradually; when the frequency is 1 MHz, the dielectric constant of the composite increases with the increase of BST content, and the dielectric loss first drops and then stabilizes; with the increase of temperature (0-400 ℃), the dielectric constant and dielectric loss of each composite at different frequencies gradually increase. The composites exhibit the hysteresis loop shape of a typical soft magnet. As the BST content increases, the saturation magnetization (Ms) gradually decreases, and the magnetic permeability decreases. The microwave property of the composite based metamaterial structure was studied. The results show that it can realize magnetic tunability.

Keywords

• ferromagnetic/ferroelectric composite media
• barium titanate
• strontium iron garnet
• dielectric property
• magnetic property
• microwave property