Magnetic properties of EuLn2O4 (Ln=rare earths)

Ternary rare earth oxides EuLn2O4 (Ln=Gd, Dy–Lu) were prepared. They crystallized in an orthorhombic CaFe2O4-type structure with space group Pnma. 151Eu Mössbauer spectroscopic measurements show that the Eu ions are in the divalent state. All these compounds show an antiferromagnetic transition at 4.2–6.3 K. From the positive Weiss constant and the saturation of magnetization for EuLu2O4, it is considered that ferromagnetic chains of Eu2+ are aligned along the b-axis of the orthorhombic unit cell, with neighboring Eu2+ chains antiparallel. When Ln=Gd–Tm, ferromagnetically aligned Eu2+ ions interact with the Ln3+ ions, which would overcome the magnetic frustration of triangularly aligned Ln3+ ions and the EuLn2O4 compounds show a simple antiferromagnetic behavior.