Influence of pressure on structural and magnetic phase transitions in La0.835Sr0.165MnO3

Measurements of the thermal expansion of a single crystal of La0.835Sr0.165MnO3 were performed under hydrostatic pressure of up to 9 kbar. The P-T phase diagram is established for the structural and magnetic phase transitions. Pressure is found to enhance the ferromagnetic coupling and to weaken the stability of the low-temperature orthorhombic phase by reducing the bending of the Mn-O-Mn bond. The decrease in the temperature TS of the structural phase transition and the increase in the Curie temperature with increasing pressure leads to the two phase boundaries crossing at a pressure of about 3 kbar. The peculiar behavior of the TS and TC in the vicinity of the crossing point demonstrates a strong coupling between structural distortion and magnetic ordering in the La0.835Sr0.165MnO3 compound. copyright 1997 The American Physical Society