Synthesis and Magnetic Properties of Ln2/3TiO3 (Ln=Pr and Nd)

The A-site-deficient perovskite compounds Ln2/3TiO3 with Ln=Pr and Nd were synthesized under an H2–Ar atmosphere at 1400 and 1450°C, respectively. The samples were found to have slight oxygen deficiencies of ~0.006 in Ln2/3TiO3–. It was also found that no single-phase compound could be prepared in air from the same initial mixtures. Their crystal structures were assigned to a double perovskite structure with the orthorhombic space group Pmmm, as in the case of La2/3TiO3. In both systems, no obvious magnetic ordering was observed between 2 and 300 K in susceptibility–temperature (–T) curves. Inverse susceptibility–temperature (1/–T) curves were found to deviate from the Curie–Weiss law below ~30 and ~90 K for Pr2/3TiO3 and Nd2/3TiO3, respectively. Magnetization–field (M–H) curves exhibited paramagnetic profiles for Pr2/3TiO3 down to 2 K and a tendency toward magnetic ordering for Nd2/3TiO3 at 2 K.