Preparation, characterization, magnetic susceptibility (Eu, Gd and Sm) and XPS studies of Ln2ZrTiO7 (Ln=La, Eu, Dy and Gd)

Bulk and nanosized pyrochlore materials Ln2ZrTiO7 (Ln=La, Eu, Dy, Gd and Sm) have been prepared by the sol–gel method. All the samples were characterized by powder X-ray diffraction, Raman and X-ray photoelectron spectroscopy. Magnetic susceptibility (χ) measurements of Gd2ZrTiO7, Sm2ZrTiO7 and Eu2ZrTiO7 were carried out by vibrating sample magnetometer in the temperature range 2–320 K. The variation of χ−1 (or χ) with temperature of Gd2ZrTiO7, Sm2ZrTiO7 and Eu2ZrTiO7 follows the Curie law, intermediate formula and the Curie–Weiss law, respectively. From the linear portion of χT vs. T−1 plot of Eu2ZrTiO7 from 2 to 15 K, the classical nearest neighbor exchange (Jcl) and dipolar interactions (Dnn) are obtained. The XPS of Ln2ZrTiO7 (Ln=La, Eu, Dy and Gd) gave characteristic peaks for Ln, Ti, Zr and O. The satellite peaks are observed only for 3d La of La2ZrTiO7.