مطالعه تاثير جايگزيني Ti به جاي Mn روي خصوصيات ساختاري و الكتريكي منگنايت La0.8Sr0.2MnO3

The effect of Ti substitution in Mn sites on the structural and electrical properties of La08Sr02MnO3 manganite

In this study, the effect of Ti substitution on structural and electrical properties of La0.8Sra2Mni_xTixO3 (0 < x< 0.075) compounds have been investigated. The double exchange interaction mechanism weakens by substituting the nonmagnetic Ti4+ ions in Mn4+ and Mn3+ sites. The results show that with increasing the doping level, metal-insulator transition temperature shifts to lower temperatures and electrical resistivity increases. Also at higher sintering temperature, lattice parameters and unit cell volume increases regularly but resistivity decreases. Electrical resistivity reduction is due to the decreasing of the grain boundary resistivity. Electrical resistivity behavior of samples is in a good agreement with small polaron hopping (SPH) model.