Synthesis, Crystal Structure and Magnetic Properties of Y<sub>3–x</sub>Cex(Fe<sub>0.5</sub>Ga<sub>0.5</sub>)<sub>5</sub>O<sub>12</sub> (<i>х</i> = 0, 0.5)

The specific magnetisation and magnetic susceptibility of ferrogranates of the composition Y3–xCex(Fe0.5Ga0.5)5O12 (x = 0, 0.5) obtained by the gel combustion method have been measured. It was found that after synthesis and subsequent crystallisation at pressure ≈ 10–2 Pa at 1023 K for 2 h, the temperature of magnetic phase transformation in the studied compositions Y3–xCex(Fe0.5Ga0.5)5O12 increases with the replacement of yttrium ions Y3+ by Ce3+. Partial substitution of iron ions in the ferrogranate lattice by gallium leads to the appearance of antiferromagnetic ordering with sufficiently high Curie-Weiss temperature Θef.