Weak ferromagnetism in a noncentrosymmetric BiPd 4 K superconductor

Abstract

We report synthesis of non-centrosymmetric BiPd single crystal by self flux method. The BiPd single crystal is crystallized in monoclinic structure with the P2 1 space group. Detailed SEM (Scanning Electron Microscopy) results show that the crystals are formed in slab like morphology with homogenous distribution of Bi and Pd. The magnetic susceptibility measurement confirmed that the BiPd compound is superconducting below 4K. Further, BiPd exhibits weak ferromagnetism near the superconducting transition temperature in isothermal magnetization (MH) measurements. The temperature dependent electrical resistivity also confirmed that the BiPd single crystal is superconducting at T c =4K. Magneto transport measurements showed that the estimated H c2 (0) value is around 7.0kOe. We also obtained a sharp peak in heat capacity Cp(T) measurements at below 4K due to superconducting ordering. The normalized specific-heat jump, C/γT c , is 1.52, suggesting the BiPd to be an intermediate BCS coupled superconductor. The pressure dependent electrical resistivity shows the T c decreases with increasing applied pressure and the obtained dT c /dP is -0.62K/Gpa.

Hydrostatic Pressure Effect on the Pinning Mechanism of α‐BiPd Noncentrosymmetric Superconductors

“…The remaining data of M ( T ) under 0.35 and 0.67 GPa are given in the Figure S1a,b, Supporting Information. α‐BiPd shows T c of 3.7 K at ambient pressure, and this value well agrees with the previous report . To show this transition clearly, these data are given as an inset in Figure a.…”

“…d T c /d P under the fields of 20, 50, 100, 150, 250, and 350 Oe are estimated by linear fitting on each plots, and the corresponding values are −0.30, −0.30, −0.37, −0.39, −0.30, and −0.18 K GPa −1 . It was noticed that the observed d T c /d P (=−0.30 K GPa −1 ) at 20 Oe from present M ( T ) upto 1 GPa was comparable with the value (≈−0.21 K GPa −1 ) measured from ρ ( T ) measurements in the same pressure range . However, it showed deviation (d T c /d P = −0.61 K GPa −1 ) in the higher pressure range (1–2 GPa) .…”

“…Platinum group materials such as Li 2 Pd 3 B, Li 2 Pt 3 B, and BiPd are the best examples of weakly correlated electronic materials with NCS–SC properties . Among these, BiPd is one of the important type II SC materials because it has several unique features . However, there are no reports on the pinning mechanism of α‐BiPd at ambient and/or under extreme conditions.…”

Unusual Dirac Fermions on the Surface of a Noncentrosymmetric α -BiPd Superconductor

“…The crystals have a platelet-like shape with shiny surfaces. As grown crystals show a superconducting transition at T c ≈ 4 K. Further elemental analysis on these single crystals are reported elsewhere [25]. ARPES measurements were carried out arXiv:1609.08947v2 [cond-mat.supr-con]…”

“…The crystals have a platelet-like shape with shiny surfaces. As grown crystals show a superconducting transition at T c ≈ 4 K. Further elemental analysis on these single crystals are reported elsewhere [25]. ARPES measurements were carried out in BESSY II (Helmholtz Zentrum Berlin) synchrotron radiation facility at the UE112-PGM2b beam line using the "1 2 -ARPES" end station equipped with SCIENTA R8000 analyzer.…”