Insulator–metal transition and the magnetic phase diagram of La1−xTexMnO3 (0.1 ≤ x ≤ 0.6)

The structural, electrical transport and magnetic properties of perovskite oxides La1−xTexMnO3 (0.1 ≤ x ≤ 0.6) have been investigated and thus the magnetic phase diagram of La1−xTexMnO3 (0.1 ≤ x ≤ 0.6) compounds as a function of temperature and the doping level x has been obtained. All samples have rhombohedral structure and undergo paramagnetic–ferromagnetic (PM–FM) transition accompanied with metal–insulator transition (MIT). A charge ordering (CO) transition begins to appear at TCO ∼ 250 K for the sample with x = 0.60. Moreover, the variation of the Curie temperature Tc and the MIT temperature Tp is quite complex and the results are discussed in terms of three factors including the average A-site cation radius 〈rA〉, the size mismatch σ2 and the Te content. In addition, there is an evidence for magnetoresistance (MR) at low-temperatures for all samples.