Magnetic and microwave absorption properties of barium hexaferrite doped with La3+ and Gd3+

Abstract

In this paper, BaLa‌xGdxFe12-2xO19 (x=0.2, 0.4, 0.6 and 0.8) were synthesized via sol-gel auto-combustion method. Fourier transform infrared spectroscopy (FTIR) of samples was represented that the bands at 400 and 500 cm-1 were related to the formation of hexaferrite phase. The (x-ray diffraction) XRD patterns were matched exactly with the structure of barium hexaferrite. (Field emission scanning electron microscopy) FESEM were represented the hexagonal shapes of all products. Magnetic analysis of barium hexaferrite were investigated by (vibrating sample magnetometer) VSM. The saturation magnetization of all samples decreased by increasing dopant’s substitution due to the different occupation sites of dopants instead of Fe3+ (64 to 36.56 emu/g) in the hexaferrite structure. The coercivity increased because of its reverse relation with saturation magnetization (5010 to 5500 Oe). Microwave absorption properties of samples was investigated by (vector network analyzer) VNA. The maximum value of reflection loss was -7.8 db at 10.4 GHz frequency in 3mm thickness for x=0.4 sample.

Keywords

• auto-combustion
• electromagnetic absorbing materials
• hexaferrite
• reflection loss
• sol-gel