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

Bulk and nanosized pyrochlore materials Ln(2)ZrTiO(7) (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 (chi) measurements of Gd2ZrTiO7, Sm2ZrTiO7 and Eu2ZrTiO7 were carried out by vibrating sample magnetometer in the temperature range 2-320 K. The variation of chi(-1) (Or chi) with temperature of Gd2ZrTiO7. Sm2ZrTiO7 and Eu2ZrTiO7 follows the Curie law, intermediate formula and the Curie-Weiss law, respectively. From the linear portion of chi T vs. T-1 plot of Eu2ZrTiO7 from 2 to 15 K, the classical nearest neighbor exchange (J(cl)) and dipolar interactions (D-nn) are obtained. The XPS of Ln(2)ZrTiO(7) (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. (C) 2010 Elsevier Inc. All rights reserved.