Effects of TM-doping on structural, magnetic and transport properties in CaTi0.8TM0.2O3 (TM = Mo, Co, and Mn)

Abstract

This paper reports the structural, morphological, magnetic, and electrical properties of the CaTi0.8TM0.2O3 (TM = Mo, Co, and Mn) system, which was prepared by the solid-state reaction method. Structural analysis was performed by X-ray diffraction (XRD) and the Rietveld refinement method, revealing that the samples crystallize in an orthorhombic structure of space group Pnma (62). Substitution generated a decrease in the lattice parameters and crystal size. The results obtained by scanning electron microscopy (SEM) show that morphology is appropriate and consistent with the reported up to now. The magnetic measurements, performed in the range of the temperature between 9 and 300 K, showed the presence of the antiferromagnetic ordering in all compounds studied. However, a second magnetic transition in lower temperatures was found in the CaTi0.8Mn0·2O3 compound. The resistivity measurements show a semiconductor type behavior in the measured temperature range 5–300 K. The data analysis showed that the transport mechanism of the polycrystalline samples is well described by the variable-range-Hopping model. The results of magnetic and electrical measurements suggest short-range antiferromagnetic interactions is present in the intermediate temperature regime.