Pairing of weakly correlated electrons in the platinum-based centrosymmetric superconductorSrPt3P

Abstract

We report a study of the normal-and superconducting-state electronic properties of the centrosymmetric compound SrPt 3 P via 31 P nuclear-magnetic-resonance (NMR) and magnetometry investigations. Essential features such as a sharp drop of the Knight shift at T < T c and an exponential decrease of the NMR spin-lattice relaxation ratio 1/(T 1 T ) below T c are consistent with an s-wave electron pairing in SrPt 3 P, although a direct confirmation in the form of a Hebel-Slichter-type peak is lacking. Normal-state NMR data at T < 50 K indicate conventional features of the conduction electrons, typical of simple metals such as lithium or silver. Our data are finally compared with available NMR results for the noncentrosymmetric superconductors LaPt 3 Si and CePt 3 Si, which adopt similar crystal structures.

Antiferromagnetic Kondo lattice compound CePt3P

“…CePt 3 Si shows antisymmetric spin-orbit coupling of the platinum 5 d electrons due to the absence of z  → − z symmetry as well as mixing spin-singlet and spin-triplet pairing states. The parity mixing alone can hardly account for the heavy fermion phenomena unless the strong electron-electron correlation effects which are ensured by the presence of Ce 3+ ions are taken into consideration together31. Correspondingly, the suppression of superconductivity in CePt 3 P may be attributed to the enhanced AFM ordering.…”

Room-temperature structural phase transition in the quasi-2D spin- 12 Heisenberg antiferromagnet Cu(pz)2(ClO4

“…In our case, this is the same for both 35 Cl sites, A hf = −10(5) mT/µ B (see parallel fit lines in Fig. 6), and was calculated by means of [14]…”

“…j)/(4c) [0.8968(3), 0.7691(3), 0.1448(4)] [0.8948(10) 0.2307(14) 0.1506(11)] 0997(10), 0.7683(14), 0.8572(11)]U iso (Å 2 ) -0.0168(5) * C4 (−)/(4c) -[0.7037(9), 0.1779(14), 0.8445(12)] U iso (Å 2 ) -0.0168(5) * D1 (8 j)/(4c) [1.0197(5),0.7807(4), 0.2700(6)] [0.0283(9), 0.2351(14), 0.2558(9)] Occ 0.978(2) * 0.961(7) * U iso (Å 2 ) 0.0428(12) 0.0254(9) * D2 (8 j)/(4c) [0.8379(5), 0.6088(4), 0.2768(5)] [0.3453(8), 0.9067(14), 0.2672(j)/(4c) [0.6505(2), 0.65082(20), 0.0041(3)] [0.8503(6), 0.1551(15), 0.9987(8)] U iso (Å 2 ) 0.0096(4) 0.0141(5) * N2 (−)/(4c) -[0.1512(6), 0.8534(15), 0.0060(8)]U iso (Å 2 ) -0.0141(5) *…”

High pressure crystal growth of the antiperovskite centrosymmetric superconductor SrPt3P

“…Such a puzzling behaviour was interpreted to reflect two-band superconductivity with equal gaps but different values for the coherence length [18]. A recent nuclear magnetic resonance (NMR) investigation showed that SrPt3P behaves as a standard metal in the normal state, being characterized by singlet pairing of the electrons and a gap function with conventional s-wave-type symmetry [19].…”

“…On the other hand, the specific heat data of SrPt3P were found to be well described within a single band, single s-wave gap approach with the zero temperature gap value of ∆0 = 1.85 meV [13]. Due to these first seemingly contradicting results, SrPt3P has attracted an increasing interest during the last years [14][15][16][17][18][19][20][21][22][23][24].…”