The Effect of Pressure on the Superconducting and Crystallographic Transitions of La3S4, La3Se4, and La3Te4.

摘要

The superconducting transition temperatures (Tc's) for La3S4 and La3Se4 vary in a non-linear fashion under hydrostatic compression to 22kbar. Both Tc and the crystallographic transformation temperature rise with pressure for La3S4 and show a maximum near 10kbar for La3Se4. Non-transforming isostructural La3Te4 exhibits a linear pressure dependence of Tc. However, the telluride undergoes a pressure induced phase transformation at approximately 70 kbar. In this case the sign of the pressure dependence is different from the sulfide and selenide. Variation of Tc with the crystallographic transformation temperature shows a new and unexpected behavior. (Author)