Structural and Electrical Transport Properties of La0.67Ba0.33Mn1-yTiyO3 Ceramics

The structural and electrical transport properties of La0.67Ba0.33Mn1-yTiyO3 manganite, with y = 0.00, 0.05, 0.10, 0.15, 0.20, 0.40 and 0.60, prepared using the solid state reaction technique have been investigated. The X-ray diffraction spectra of the Ti substituted samples showed the formation of single phase compound with Pm3m cubic structure except for the y = 0.60 sample, which showed La2Ti2O7 phase formation. Lattice parameter increased with Ti content and then decreased at y = 0.60. Resistivity versus temperature study showed that only samples with y = 0.05 and 0.10 exhibited both metallic and semiconductor-like behaviour with the metal-insulator transition temperature, T-p of 167 K and 43 K, respectively. At higher Ti concentration the samples only showed the semiconducting behaviour. At T < T-p the resistivity curves followed the rho = rho(o1) + rho T-1(2) relation and for T > T-p, the curves can be fitted with the nearest neighbour hopping (NNH), variable range hopping (VRH) or/and the small polaron hopping (SPH) models.