Magnetic and electric characteristics and abnormality of low-temperature resistivity in La0.67–xErxSr0.33MnO3(0.00≤x≤0.20) system

M-T curves, ρ-T curves, and MR-T curves of La0.67–xErxSr0.33MnO3 (x=0.00, 0.10, 0.20) system were studied by experiments. The experiments showed that: with increasing the doping amount, the magnetic structure of the system transformed from long-range ferromagnetic ordering to spin-cluster glass state, and M-T curves bent up in the extremely low temperature range; the resistivity of the system increased with increasing doping amount and exhibited the minimum phenomenon of low-temperature resistivity. The variation of the magnetic and electric properties came from the extra magnetic coupling induced by the doping and from the Kondo effect induced by the lattice distortion and local magnetic moments which was similar to that induced by the scattering of magnetic impurities on electron spins.