Colossal magnetoresistance behavior and ESR studies of La1-xTexMnO3 (0.04≤x≤0.2) -: art. no. 014426

In this paper, we report the magnetic and electrical properties of the Te-doped lanthanum manganite perovskite compound La1-xTexMnO3 and the related electron spin resonance (ESR) study. This is a material with rhombohedral structure and it shows good colossal magnetoresistance behavior. The magnetoresistance ratio MR=[rho(0)-rho(H)]/rho(0) is about 63% for x=0.04 in an applied magnetic field of 40 kOe. The resistivity of the compounds is affected by temperature and the amount of Te doping. The temperature dependence of the resistivity showed that the conductivity above the Curie temperature was dominated by the hopping of the small polarons, and the resistance was attributed to the electron-phonon and magnon scattering mechanism below the metal-insulator transition temperature. The ESR investigation indicated that the compound was in the paramagnetic phase above 230 K, and in the single ferromagnetic state below 170 K. In the temperature range of 230 to 170 K, the compound showed phase separation phenomena.