Structure and metal-insulator transition in La0.7(Ca1-xCex)0.3MnO3

[[abstract]]According to the double-exchange theory in divalent-doped LaMnO3, manganese ion exists in trivalent and tetravalent states. But if the rare earth ion is partially replaced by some tetravalent ion the corresponding amount of manganese will be converted into a divalent state. We will present the study of La0.7Ce0.3MnO3 systematically replacing Ca by Ce. Since Ce is supposed to be tetravalent, in La0.7Ce0.3MnO3 the mixed valent states of manganese ions are Mn2+/Mn3+ instead of Mn4+/Mn3+. It is shown that with increasing Ce content in La0.7(Ca1-xCex)0.3MnO3 metal-insulator transition, which is observed for x