LAUSR

Abstract The present study investigates electromagnetic properties, as well as microstructural and thermal stability, of low temperature fired MgCuZn ferrite with the addition of various amounts of Bi 2 O 3 . To achieve better performance at low sintering temperature, ceramic specimens were fabricated using nano-sized precursor powders through the nitrate-citrate auto-combustion method. X-ray diffraction study shows the formation of single phase spinel structure without any impurity phases. Compared with the additive-free sample, the addition of Bi 2 O 3 increases the density of all specimens. Scanning electron microscopy micrographs of samples indicate that Bi 2 O 3 content significantly affects densification through grain growth promotion. Excessive amounts of Bi 2 O 3 , however, lead to abnormal grain growth. Moreover, the sample with 0.25 wt% Bi 2 O 3 shows the highest density and grain shape uniformity as well as the lowest porosity. Dynamic magnetic properties were studied in a frequency range of 1–90 MHz, using an impedance analyzer. Results reveal that the sample with a low amount of additive (0.25 wt%) has the highest saturation magnetization, initial permeability (at 1 MHz), and quality factor, whereas it's Curie temperature slightly decreases. With the further increase of Bi 2 O 3 content, however, the initial permeability and saturation magnetization of samples deteriorate gradually.