Heat-treatment Effect on Z-type Hexaferrite for RF Device Application

Heat-treatment Effect on Z-type Hexaferrite for RF Device Application

The Z-type hexaferrite Ba1.5Sr1.5Co2Fe24O41 was synthesized by using a solid state reactionmethod under various heat-treatment conditions. The crystal structure and magnetic properties athigh frequency were characterized by on x-ray diffractometer, network analyzer, vibrating samplemagnetometer, and M¨ossbauer spectrometer. The Ba1.5Sr1.5Co2Fe24O41 samples prepared by usingthe step calcination (SC12) process showed the considerably improved permeability and magneticloss compared to those prepared by using the other processes due to the complete formation of Ztypephase from the calcination. When Co2Z sample prepared by using SC12 process was sinteredat 1125 C and cooled at a slow rate, the value of magnetic loss tanμ remained below 0.1 up to750 MHz, and at 750 MHz, the values of permeability, permittivity, and dielectric loss were μ0 =7.9, "0 = 10.9, and tan" = 0.01, respectively.

The Z-type hexaferrite Ba1.5Sr1.5Co2Fe24O41 was synthesized by using a solid state reactionmethod under various heat-treatment conditions. The crystal structure and magnetic properties athigh frequency were characterized by on x-ray diffractometer, network analyzer, vibrating samplemagnetometer, and M¨ossbauer spectrometer. The Ba1.5Sr1.5Co2Fe24O41 samples prepared by usingthe step calcination (SC12) process showed the considerably improved permeability and magneticloss compared to those prepared by using the other processes due to the complete formation of Ztypephase from the calcination. When Co2Z sample prepared by using SC12 process was sinteredat 1125 C and cooled at a slow rate, the value of magnetic loss tanμ remained below 0.1 up to750 MHz, and at 750 MHz, the values of permeability, permittivity, and dielectric loss were μ0 =7.9, "0 = 10.9, and tan" = 0.01, respectively.