[Phase separation and transport behaviors in La(0.7 - x)Dy(x)Sr0.3MnO3 system].

The influence of Dy doping (0.00 < or = x < or = 0.30) on magnetic and electric properties of La0.7Sr0.3MnO3 was studied by measuring M-T curves, M-H curves, ESR curves, rho-T curves and MR-T curves of the samples. The experimental results indicate that all samples undergo the transition from paramagnetism to ferromagnetism at T(C). When T < T(C), the doped samples enter the cluster-spin glass state, and the antiferromagnetism is exhibited at lower temperature. For the samples x = 0.2, the phase separation occurs at the temperature far above T(C), the variation in magnetic structure caused by Dy doping leads to colossal magnetoresistance.