Magnetic properties of layered perovskites NaLnTiO(4) (Ln = Sm, Eu, and Gd)

摘要

The magnetic properties of the layered perovskite compounds NaLnTiO(4) (Ln = Sm, Eu, and Gd) are reported, Their Be susceptibilities were measured from 4.5 to 320 K, The Mossbauer spectrum of Eu-151 and the electron paramagnetic resonance (EPR) spectrum of Gd3+ mere also measured at room temperature, NaEuTiO4 shows Vara Vleck paramagnetism which corresponds to the singlet ground state F-7(0) of Eu3+ ions, with a spin-orbit coupling constant lambda =323 cm(-1). NaSmTiO4 also behaves as a Van Vleck paramagnet. The magnetic susceptiblity of NaGdTiO4 follows the Curie law. The Mossbauer spectrum of NaEuTiO4 clearly shows that Eu is ins the trivalent state, and a quadrupole interaction is found to exist in this compound, From the EPR measurement the g value of Gd3+ in NaGdTiO4 is determined to be 1.99, Both the magnetic susceptibility results and the EPR measurements show that Gd3+ ion in this compound is scarcely affected by the crystal field. (C) 1998 Academic Press. [References: 11]