The coupling interaction between charge ordering and spin ordering in a CO/C-type AFM system

In order to experimentally probe the complicated interaction between charge ordering and spin ordering in manganites, two sets of samples Ca0.875Ce0.125Mn1−xCrxO3 and Ca0.875Ce0.125Mn1−yGayO3 (0.0≤x,y≤0.075) have been studied by means of electrical transport measurements, magnetization measurements and electron spin resonance. A large difference between the evolution of the charge ordering temperature Tco in the Cr doping and the Ga doping cases is found. For Cr-doped samples, the Tco decreases to 150 K at x=0.025 and then disappears when x exceeds 0.05. But in Ga-doped samples, although the Tco decreases to 150 K at y=0.025, it begins to increase with further increase of the doping level. All these phenomena indicate that charge ordering formation is dominated by the spin ordering. As a result, it is experimentally proved that there is strong coupling interaction between charge ordering and spin ordering in the CO/C-type AFM system.