Cation ordering and microwave dielectric properties of a LiGaTiO4 spinel by quenching

The cation order/disorder behavior and microwave dielectric properties of spinel-structured LiGaTiO4 (LGT) ceramics was characterized. The ordered spinel with Imma is a predominant crystalline phase for furnace-cooled LGT (LGT-F) ceramic, while the disordered spinel with Fdm appears by quenching. The fractions of ordered and disordered spinels were estimated by using synchrotron X-ray diffraction profiles and the Rietveld method and it was found that the fraction of disordered spinel increased with increasing quenching temperatures. The fractions of the ordered and disordered spinel in the LGT-F ceramic were estimated to be 47.6% and 52.4%, while those of the ordered and disordered spinel were 21.7% and 78.3% when the LGT ceramic was quenched at 1200 °C. Although the influence of the presence of ordered/disordered spinels on the εr and TCf values of LGT was small, the Q · f values strongly depended on the fraction of the ordered spinel.