Magnetic properties of rare earth rhenium oxides Ln3ReO7 (Ln = Y, Er–Lu) with fluorite-related structure

Ternary rare earth rhenium oxides Ln3ReO7 (Ln = Y, Er–Lu) have been prepared. Their X-ray diffraction measurements and the Rietveld analysis show that these compounds have an orthorhombic superstructure of fluorite-type with space group C2221 (for Ln = Y, Er, Tm) or a defect-fluorite structure Fm 3 m (for Ln = Yb, Lu). The zero-field-cooling and field-cooling magnetic susceptibility for Y3ReO7 diverse when the temperature is decreased through 10 K. At the same temperature, specific heat anomaly is also observed. The results of the specific heat measurements for Tm3ReO7 and Yb3ReO7 indicate the existence of magnetic anomaly below 7 and 2.2 K, respectively. On the other hand, Er3ReO7 and Lu3ReO7 are paramagnetic down to 1.8 K.