Sol-gel synthesis of copper(Ⅱ) and titanium(Ⅳ) ions co-doped barium ferrite submicrometer crystals and their microwave absorption performance

摘要

Copper(Ⅱ)-titanium(Ⅳ)-doped barium ferrite (Ba(CuTi)_xFe_(12-2x)O_(19), x = 0, 0.5, 0.75, 1, 1.25) were prepared by the sol-gel method. The X-ray diffraction patterns of Ba(CuTi)_xFe_(12-2x)O_(19) proved that M-type barium hexagonal ferrite was formed. From the field emission scanning electron microscopy images, hexagon shaped grains could be obviously observed in Ba(CuTi)_xFe_(12-2x) O_(19) when x = 0.5, but its morphology tended to be irregular when x ≥ 0.75. In addition, the inductively coupled plasma atomic emission spectrometry test revealed that the doping limit of x was 0.75. Based on the electromagnetic parameters measured by the vector net-analyzer in the frequency of 2-18 GHz, the maximum reflection loss value of -37 dB at 16.7 GHz was observed for Ba(CuTi)_x Fe_(12-2x)O_(19) (x = 0.75) with a matching thickness of 1.6 mm. Therefore, Ba(CuTi)_xFe_(12-2x)O_(19) may be a good candidate as the microwave absorbing material for the applications in the field of high frequency.