Phase diagram of La1-xCaxMnO3 for x≥0.5

The low-temperature phase diagram of the La1-xCaxMnO3 compound for 0.5less than or equal toxless than or equal to0.9 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 3 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. (C) 2003 Elsevier B.V. All rights reserved.