掺杂 La 对 YFeO₃陶瓷吸波性能的影响

La-doped YFeO₃ ceramics, namely Y_1-xLa_xFeO₃ (x = 0.1, 0.2, 0.3, 0.4) were prepared by sol-gel method and high-temperature sintering method, then the YFeO₃ ceramics before and after La doping was characterized by means of scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS) and network vector analyzer (VNA). So that the effect of the La³⁺ doping amount on the micromorphology, phase constituents, chemical composition, electromagnetic parameters and microwave absorption performance of Y_1-xLa_xFeO₃ were studied. The result shows that as the La doping amount increases, the grain size is gradually decreasing and the grain boundaries are gradually blurred of the ceramics, which may be related to the enhanced preferential orientation of grains and incomplete replacement of the doping atoms. The analysis results confirm that the prepared ceramics consist merely of the YFeO₃-type phase, and La³⁺ can replace the Y³⁺ position in the YFeO₃ crystal. It is clear that an appropriate amount of La doping can effectively increase the impedance matching and attenuation coefficients of YFeO₃ ceramic powder. The increase in the dielectric constant may be attributed to the hopping of electrons between Fe³⁺ and Fe²⁺ in the case of La doping. The effective absorption broadband (RL ≤ -10 dB) of Y_0.7La_0.3FeO₃ can reach 2.84 GHz.