Magnetic properties and microstructure of YIG thick films prepared by screen printing

초록

YIG(yttrium iron garnet) thick films which have been well known for magnetic materials as microwave devices were prepared on the YSZ(yttrium stabilized zirconia) substrate by screen printing process. To develop high performance YIG thick films for the applications of microwave devices, we have studied the microstructure and the magnetic properties of saturation magnetization and ferromagnetic resonance line width. From the result of TEM analysis, a small amount of Zr4+ ion was detected in a grain of YIG thick films due to the diffusion from a substrate. The single phase was obtained for all YIG thick films by sintering at 1400K. Y2.9Ca0.1Fe4.9Zr0.1O12(Y3-xCaxFe5-xZrxO12, where x=0.1) thick film exhibited good magnetic properties of 1550G, 116 Oe. In order to enhance the magnetic properties of YIG thick films, the pressure was applied to each thick film in a CIP(Cold Isostatic Pressing) equipment. It has been concluded that CIP plays a role reducing the porosity of the thick films. We derived the relationship between H value and porosity. Due to the effect of CIP on YIG thick films, Ms increased up to 1680G and H decreased to about 79 Oe with applied pressure.