Muon spin rotation and relaxation inPr1−xNdxOs4Sb12: Paramagnetic states

Abstract

Positive-muon (µ + ) Knight shifts have been measured in the paramagnetic states of Pr1−xNdxOs4Sb12 alloys, where x = 0, 0.25, 0.45, 0.50, 0.55, 0.75, and 1.00. In Pr-substituted NdOs4Sb12 (x ≤ 0.75), but not in NdOs4Sb12, Clogston-Jaccarino plots of µ + Knight shift K versus magnetic susceptibility χ exhibit an anomalous saturation of K(χ) at ∼ −0.5% for large susceptibilities (low temperatures), indicating a reduction of the coupling strength between µ + spins and 4f paramagnetism for temperatures < ∼ 15 K. We speculate that itinerant Pr 3+ quadrupolar excitations, invoked to mediate the superconducting Cooper-pair interaction, might modify the µ + -4f ion indirect spin-spin interaction.

Nodeless superconductivity and preserved time-reversal symmetry in the noncentrosymmetric Mo3P superconductor

“…The coupling constant [i.e., the coefficient in Eq. (A.1)] may become temperaturedependent for χ < 0.5 × 10 −4 emu/mol 68 . From the slope dK/dχ of the K-χ plot for T < 50 K, by assuming a standard electronic g-factor of 2.0, the relation K = gA hf χ + K offset gives a hyperfine coupling constant A hf = −0.082 T/µ B and a zero intercept of 0.025%.…”

Electron-phonon superconductivity in the filled skutterudites LaRu4P12, LaRu4As12 , and Tütüncü1, Karaca2, Srivastava3 2017Phys. Rev. B

“…Filled skutterudite pnictides with the general formula LnT 4 X 12 (Ln = lanthanide, T = transition metal, X = pnictogen) have received considerable attention in recent years because of their interesting physical properties at low temperature, such as excellent thermoelectric performance [1][2][3][4], intermediate-valence [5], non-Fermi-liquid behavior [6], magnetic ordering [7][8][9], metal-to-insulator transition [10][11][12][13][14][15][16], semiconducting behavior [17][18][19][20][21][22][23], and heavy-fermion behavior [24][25][26][27][28][29][30][31][32][33][34][35][36]. Also, lanthanum compounds display interesting superconducting behavior at low temperatures [37][38][39][40][41][42][43][44][45][46][47].…”