Аннотация
Double ferrites ErCaFe 2 O 5.5 , ErSrFe 2 O 5.5 , and ErBaFe 2 O 5.5 were synthesized by solid-state reactions from erbium and iron(III) oxides and calcium, strontium, and barium carbonates. The compounds were found to crystallize in the orthorhombic system. Their unit cell parameters were determined by X-ray powder diffraction; their densities were measured.