Synthesis of bulk samples of Bi- and Ga-substituted yttrium iron garnet by the modified method of gel combustion using ethylene glycol

Single-phase polycrystalline samples of Bi- and Ga-substituted yttrium iron garnet Y1.8Bi1.2Fe3.5Ga1.5O12 were obtained by the gel combustion method. Ethylene glycol was used as a gelling agent. The crystal structure and microstructure of bulk samples obtained under different annealing regimes have been studied. The position of the diffraction peaks corresponded to the cubic structure of the garnet. The dependence of the average grain size dav on the annealing temperature and time is shown: at 780 ºС (5 h) dav ≈ 170 nm, at 780 ºС (12 h) dav ≈ 230 nm, and at 1000 ºС (12 h) dav ≈ 500 nm.