Investigation of the transport, magnetic and flux pinning properties of the noncentrosymmetric superconductor TaRh2B2 under hydrostatic pressure

摘要

The bulk superconducting properties of polycrystalline TaRh2B2 under pressure are investigated with transport resistivity [rho(T)], and dc magnetization [M(T) and M(H)] measurements up to similar to 3 GPa, and 1 GPa respectively. The application of hydrostatic pressure leads to a decrease in T-c for both magnetic [dT(c)/dP is -0.4 K/GPa (0 <= P <= 1 GPa)] and transport [(dT(c)/dP) is -0.02 K/GPa (0 <= P <= 1 GPa) and -0.06 K/GPa (1 <= P <= 2.5 GPa)] measurements. At 2.5 GPa the upper critical field, mu H-0(c2)(0), and the irreversible field, mu H-0(irr) (0), are found to be (11.8 +/- 0.2) T and (6.5 +/- 0.1) T respectively. The critical current density, J(c) (at mu H-0 = 0 T), decreases from 6.5 x 10(5) A/cm(2) (0 GPa) to 2.5 x 105 A/cm(2) (0.9 GPa) at 4.3 K. The flux pinning and J(c)(H) in TaRh2B2 are significantly affected by the application of external pressure. It is seen that surface and volume flux pinning coexist both at ambient pressure and at high pressure. We infer that the pinning energy and superconducting properties are suppressed by external pressure.