Effect of pressure on transport and magnetotransport properties in CaFe₂As₂ single crystals

The effects of pressure generated in a liquid-medium clamp pressure cell on the in-plane and c-axis resistance, temperature-dependent Hall coefficient, and low-temperature magnetoresistance in CaFe₂As₂ are presented. The T−P phase diagram, including the observation of a complete superconducting transition in resistivity delineated in earlier studies is found to be highly reproducible. The Hall resistivity and low-temperature magnetoresistance are sensitive to different states/phases observed in CaFe₂As₂. Auxiliary measurements under uniaxial c-axis pressure are in general agreement with the liquid-medium clamp cell results with some difference in critical pressure values and pressure derivatives. The data may be viewed as supporting the potential importance of nonhydrostatic components of pressure in inducing superconductivity in CaFe₂As₂.