The effects of milling time on structure, magnetic properties and microwave absorption capability of strontium lanthanum ferrite compounds

Abstract

A series of lanthanum oxide doped of Strontium ferrite material has been produced by using a solid-state reaction method with the composition of (1-x) SrO: (x)La2O3: (6)Fe2O3, where x = 0.2 mol. The solid-state reaction method consists of mixing, milling with time duration of (hour) 0.5; 1.0 and 1.5, pressing, annealing at 800 ° C for 1 hour, and sintering at 1100 °C for 3 hours. XRD, VSM, and VNA characterizations have been carried out to analyze the structure, magnetic properties, and microwave absorption capability, respectively. The characterization results showed the appearance of Sr0,5La0,5Fe12O19, SrFe12O19 and Fe2O3 crystal phases. The samples with a milling time of 1 hour produced the highest Sr0.5La0.5Fe12O19 crystal phase and the smallest crystal size and also the highest M s value. These factors result in to achieve the best microwave absorption capability. The highest microwave absorption is-35.99 dB at a frequency of 7.69 GHz which is attained by the samples with a milling time of 1 hour. Increasing the milling time by more than 1 hour will cause the sample to agglomerate so that the crystal size increases, the Sr0.5La0.5Fe12O19 crystal phase decreases, the M s value also decreases, and ultimately causes absorption capability of the microwave also decreases. Generally, the 1 hour milling time process yields the magnetic material which is very promising for electromagnetic interference (EMI) absorption applications for frequencies of 8-12 GHz (X-Band).