Synthesis and characterization microwave absorber properties of La_0.7(Ca_1-xSr_x)_0.3MnO₃ prepared by Sol-Gel method

In this research, structural engineering of lanthanum-manganate-based material was studied, starting with material synthesizing La_0.7(Ca_1-xSr_x)_0.3MnO₃ with variation of x=0; 0.1; 0.2; and 0.3 using the sol-gel method as a microwave material. The effects of Sr substitution on the stucture, size of grain, and microwave-absorbing properties were investigated in detail by various analytical methods. Using XRD (X-Ray Diffraction) showed that the sample had single phase and orthorombic structure (space group of Pnma), substitution of Sr^{2 +} ions did not cause changes in structure. Characterized using SEM (Scanning Electron Microscope) showed change in grain size which increase when given Sr substitution. Characterized using VNA (Vector Network Analyzer) in the 8-12 GHz range shows that the sample La_0.7(Ca_1-xSr_x)_0.3MnO₃ with x=0 has been able to absorb up to 55.64% microwaves at 10.44GHz. The study concluded the material of La_0.7(Ca_1-xSr_x)_0.3MnO₃ have a good potential to be a candidate of microwave absorbing materials. (paper)