Temperature-dependent phase evolution and reflection loss of lanthanum orthoferrite (LaFeO₃)

LaFeO₃ material was synthesized using the solid-state reaction method with High Energy Milling (HEM). The samples were subjected to varying sintering temperatures of 800, 900, 1000, 1100, and 1200 °C for 3 h. X-ray diffraction (XRD) analysis revealed that the LaFeO₃ phase formed in all samples; however, a single-phase LaFeO₃ structure was observed only at sintering temperatures of 1100 and 1200 °C. Scanning electron microscopy (SEM) analysis indicated that the average particle size increased significantly from 235.533 nm to 909.217 nm as the sintering temperature was raised from 800 to 1200 °C. Energy-dispersive spectroscopy (EDS) confirmed that all samples contained only La, Fe, and O elements. Magnetic property measurements using a vibrating sample magnetometer (VSM) demonstrated a slight decrease in saturation magnetization as the sintering temperature increased from 800 to 1200 °C. The highest saturation magnetization value of 0.27 emu/g and the maximum coercivity value of 1.350 Oe were observed at a sintering temperature of 800 °C. Vector network analyzer (VNA) measurements showed that the minimum reflection loss value exceeded −10 dB, with all samples exhibiting a sufficiently wide effective absorption bandwidth (EAB). These characteristics suggest that LaFeO₃ has strong potential for development as a microwave-absorbing material in the C-band frequency range (4–8 GHz).