Phase diagram of La1−xCaxMnO3 for x⩾0.5

Abstract The low-temperature phase diagram of the La 1− x Ca x MnO 3 compound for 0.5⩽ x ⩽0.9 is presented, using elastic neutron diffraction data. The neutron diffraction patterns can be consistently explained by considering the existence of four phase boundaries x =0.5–0.55, 2 3 , 0.80–0.85 and 1, at which the material forms a distinct crystallographic and magnetic phase. At the intermediate x it consists of a mixture of the two adjacent boundaries, according to the lever rule. The variation of the T N and of the structural transition temperature with the Ca doping content can be constructed by applying the lever rule. A final interesting result is that for x =0.80–0.90 the magnetic and the structural transition occur simultaneously.