Influence of pressure on structural and magnetic phase transitions inLa0.835Sr0.165MnO3

Abstract

Measurements of the thermal expansion of a single crystal of La{sub 0.835}Sr{sub 0.165}MnO{sub 3} 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 T{sub S} 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 T{sub S} and T{sub C} in the vicinity of the crossing point demonstrates a strong coupling between structural distortion and magnetic ordering in the La{sub 0.835}Sr{sub 0.165}MnO{sub 3} compound. {copyright} {ital 1997} {ital The American Physical Society}