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

Abstract

In order to experimentally probe the complicated interaction between charge ordering and spin ordering in manganites, two sets of samples Ca 0.875Ce 0.125Mn 1− x Cr x O 3 and Ca 0.875Ce 0.125Mn 1− y Ga y O 3 ( 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 T co in the Cr doping and the Ga doping cases is found. For Cr-doped samples, the T co decreases to 150 K at x = 0.025 and then disappears when x exceeds 0.05. But in Ga-doped samples, although the T co 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.