Reentrant spin glass behavior in La0.8Sr0.2Mn1-xTixO3 manganites

In this study, the effect of Ti substitution on structural, electrical and magnetic properties of La0.8Sr0.2Mn1-xTixO3 (0 <= x <= 0.075) are investigated by XRD, electrical resistivity and ac susceptibility measurements. The XRD refinement result indicates that the lattice parameters and volumes increase by an increase of the Ti doping level. The resistivity measurement results show that by increasing the Ti doping level, the metal insulator transition temperatures decrease and system becomes an insulator. The paramagnet-ferromagnet transition temperature, T-c also decreases as the Ti content increases. The reentrant spin glass (RSG) state exists in the x = 0.05 and 0.075 samples. The RSG behavior is mainly ascribed to an increase of disorder in the FM matrix induced by the random Ti impurity substitution. (C) 2009 Elsevier Ltd. All rights reserved.