Fe doping effects on the magnetic and transport properties in La0.67Sr0.33Mn1−xFexO3

The X-ray diffraction patterns, susceptibility, electron magnetic resonance and resistivity in La0.67Sr0.33Mn1−xFexO3 have been studied systematically. With increasing Fe concentration, Tc and the shift of resonance field Hr decrease, the resistivity (two resistivity transition peaks were observed in x=0.07, 0.10) increases, but the lattice constants remain almost unchanged. When x=0.23, the spin glass-like state is observed and the system behaves insulator-like. The above results strongly suggest that the dopant Fe ions weaken the double exchange interaction.