La1.4Te0.6Mn1.8Co0.2O6 double perovskite: Structural, magnetic, and electrical transport properties

The present work involves the study of structural, magnetic and electrical transport properties of nanocrystalline La1.4Te0.6Mn1.8Co0.2O6 sample, which was synthesized using the sol-gel technique. The structural characterization shows that the present nanocrystalline sample has been crystallized in rhombohedral crystal structure with R3¯ space group as determined by the X-ray diffraction data. The average crystallite size was calculated to be ∼ 25 nm using Debye Scherer relation. The scanning electron microscopy (SEM) image shows that the formed particles are almost uniform in size and having average particle size ∼ 125 nm. The SEM image confirmed the homogeneity of the nanocrystalline sample. Temperature dependence of magnetization measurement determined that the nanocrystalline La1.4Te0.6Mn1.8Co0.2O6 sample undergoes the transition from paramagnetic to ferromagnetic state at ∼ 184 K. From resistivity measurement as a function of temperature, semiconducting behavior was observed in nanocrystalline La1.4Te0.6Mn1.8Co0.2O6 sample. The hopping distance (Rh) and the density of states N(EF) at room temperature were found to be 37.98 A and 29.75 x 1018 eV−1cm−3 respectively as calculated from the VRH fitted data.