Radiation Losses in the Microwave X Band in Al-Cr Substituted Y-Type Hexaferrites

We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba_2Mg_2Al_x/2Cr_x/2Fe_12-xO_22 (x=0, 0.5 and 1.0). The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. Ba_2Mg_2Fe_12O_22 hexaferrite shows radiation loss of -37.25 dB (99.999% loss) at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08 emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.