Magnetic ordering of divalent europium in double perovskites Eu2LnTaO6 (Ln=rare earths): Magnetic interactions of Eu2+ ions determined by magnetic susceptibility, specific heat, and 151Eu Mössbauer spectrum measurements

Structures and magnetic properties of double perovskite-type oxides Eu2LnTaO6 (Ln=Eu, Dy–Lu) were investigated. These compounds adopt a distorted double perovskite structure with space group P21/n. Magnetic susceptibility, specific heat, and 151Eu Mössbauer spectrum measurements show that the Eu2+ ions at the 12-coordinate sites of the perovskite structure are antiferromagnetically ordered at ∼4 K, and that Ln3+ ions at the 6-coordinate site are in the paramagnetic state down to 1.8 K.