Insight into Kondo screening in the intermediate-valence compound SmOsSb uncovered by soft X-ray magnetic circular dichroism

Saito, Yuji; Fujiwara, Hidenori*; Yasui, Akira*; Kadono, Toshiharu*; Sugawara, Hitoshi*; Kikuchi, Daisuke*; Sato, Hideyuki*; Suga, Shigemasa*; Yamasaki, Atsushi*; Sekiyama, Akira*; et al.

Physical Review B, 102(16), p.165152_1 - 165152_8, 2020/10

https://doi.org/10.1103/PhysRevB.102.165152

Magnetic-field-induced charge order in the filled skutterudite SmRuP; Evidence from resonant and nonresonant X-ray diffraction

Matsumura, Takeshi*; Michimura, Shinji*; Inami, Toshiya; Hayashi, Yuya*; Fushiya, Kengo*; Matsuda, Tatsuma*; Higashinaka, Ryuji*; Aoki, Yuji*; Sugawara, Hitoshi*

Physical Review B, 89(16), p.161116_1 - 161116_5, 2014/04

https://doi.org/10.1103/PhysRevB.89.161116

The antiferromagnetic ordered phase below = 16.5 K and the unresolved intermediate phase between and (= 14 K) in SmRuP have been studied by resonant and nonresonant X-ray diffraction. In the intermediate phase, nonresonant Thomson scattering with = (1,0,0) is induced by applying a magnetic field. This phenomena is caused by atomic displacements reflecting the charge order in the band, as predicted theoretically. Simultaneously, the antiferromagnetic moment of Sm is enhanced along the field direction, which is considered to reflect the staggered ordering of the - crystal-field states. The present results show that the orbital-dependent - hybridization in association with the nesting instability in the band gives rise to the unconventional charge order similarly with PrRuP and PrFeP.

Magnetic excitation in totally symmetric staggered ordered phase of PrFeP

Iwasa, Kazuaki*; Hao, L.*; Kogi, Masafumi*; Kuwahara, Keitaro*; Mignot, J.-M.*; Sugawara, Hitoshi*; Aoki, Yuji*; Matsuda, Tatsuma; Sato, Hideyuki*

Journal of the Physical Society of Japan, 81(9), p.094711_1 - 094711_9, 2012/09

https://doi.org/10.1143/JPSJ.81.094711

Suppression of time-reversal symmetry breaking superconductivity in Pr(OsRu)Sb and PrLaOsSb

Shu, L.*; Higemoto, Wataru; Aoki, Yuji*; Hillier, A. D.*; Oishi, Kazuki*; Ishida, Kenji*; Kadono, Ryosuke*; Koda, Akihiro*; Bernal, O. O.*; MacLaughlin, D. E.*; et al.

Physical Review B, 83(10), p.100504_1 - 100504_4, 2011/03

https://doi.org/10.1103/PhysRevB.83.100504

Zero-field muon spin relaxation experiments have been carried out in the Pr(OsRu)Sb and PrLaOsSb alloy systems to investigate broken time-reversal symmetry (TRS) in the superconducting state, signaled by the onset of a spontaneous static local magnetic field B. In both alloy series B initially decreases linearly with solute concentration. Ru doping is considerably more efficient than La doping, with a 50% faster initial decrease. The data suggest that broken TRS is suppressed for Ru concentration 0.6 but persists for essentially all La concentrations. Our data support a crystal-field excitonic cooper pairing mechanism for TRS-breaking superconductivity.

Possible low-energy excitations of multipoles in SmRuP probed by muon spin relaxation

Ito, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Heffner, R. H.; Nishida, Nobuhiko*; Sato, Kazuhiko*; Sugawara, Hitoshi*; Aoki, Yuji*; Kikuchi, Daisuke*; Sato, Hideyuki*

Physica B; Condensed Matter, 404(5-7), p.761 - 764, 2009/04

https://doi.org/10.1016/j.physb.2008.11.179

We report on detailed longitudinal field (LF) SR studies in SmRuP in order to characterize magnetic fluctuations in a magnetically ordered state below K. A magnitude and fluctuation rate of the fluctuating field are derived as functions of temperature from LF dependence of the longitudinal relaxation rate. Possible low-energy excitations of magnetic multipoles are discussed.

Muon spin relaxation and hyperfine-enhanced Pr nuclear spin dynamics in Pr(Os,Ru)Sb and (Pr,La)OsSb

Shu, L.*; MacLaughlin, D. E.*; Aoki, Yuji*; Tsunashima, Yoshino*; Yonezawa, Yuki*; Sanada, Shotaro*; Kikuchi, Daisuke*; Sato, Hideyuki*; Heffner, R. H.; Higemoto, Wataru; et al.

Physical Review B, 76(1), p.014527_1 - 014527_8, 2007/07

https://doi.org/10.1103/PhysRevB.76.014527

Evolution of local magnetic state in SmRuP probed by muon spin relaxation

Ito, Takashi; Higemoto, Wataru; Oishi, Kazuki; Fujimoto, Tatsuya*; Heffner, R. H.; Nishida, Nobuhiko*; Sato, Kazuhiko*; Sugawara, Hitoshi*; Aoki, Yuji*; Kikuchi, Daisuke*; et al.

Journal of the Physical Society of Japan, 76(5), p.053707_1 - 053707_4, 2007/05

https://doi.org/10.1143/JPSJ.76.053707

A filled skutterudite compound SmRuP shows metal-insulatortransition at =16.5K with magnetic anomaly. A possibility of magnetic octupole ordering has been discussed on the basis of multipole degrees of freedom belonging to thecrystalline-electric-field ground state. We investigated local magnetic states in the ordered state by using the muon spin relaxation method. An increase of muon spin relaxation rate was detected in zeroapplied field just below , indicating time-reversal-symmetry breaking in the ordered state. This result suggests that the order parameter includes magnetic octupole and/ordipole. Magnitude of the internal field at the muon site monotonically increases with decreasing temperature, growing steeply below =3K. The longitudinal relaxation rate has a maximum at around , suggesting suppression of magnetic fluctuations. We discussed these experimental facts on the basis of the multipoledegrees of freedom.

Resonant X-ray scattering of PrRuP

Ishii, Kenji; Tsutsui, Satoshi*; Hao, L.*; Hasegawa, Tomoo*; Iwasa, Kazuaki*; Tsubota, Masami; Inami, Toshiya; Murakami, Yoichi*; Saha, S. R.*; Sugawara, Hitoshi*; et al.

Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.e178 - e180, 2007/03

PrRuP shows a metal-insulator (MI) transition at 62 K accompanied by a structural phase transition. Because LaRuP without electrons does not shows the MI transition, electrons in the Pr atom plays an important role in the transition. In order to elucidate a modulation of electronic states of Pr, we have carried out a resonant X-ray scattering study of PrRuP at Pr - and -edges. Below , resonant signal at the absorption main-edge was successfully observed at the superlattice reflections of the modulation vector in addition to the energy-independent component from the lattice distortion. Because the reflection contains the difference of anomalous scattering factors between two Pr atoms in the unit cell, two different electronic states are actually ordered below . Furthermore we found that the polarization of X-ray is mostly unrotated even at the resonance, which indicates that the resonant scattering in PrRuP is almost isotropic.

Time reversal symmetry breaking in superconducting (Pr,La)OsSb and Pr(Os,Ru)Sb

Shu, L.*; Higemoto, Wataru; Aoki, Yuji*; Frederick, N. A.*; Yuhasz, W. M.*; Heffner, R. H.; Oishi, Kazuki; Ishida, Kenji*; Kadono, Ryosuke*; Koda, Akihiro*; et al.

Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.551 - 553, 2006/11

Inelastic neutron scattering study on low-energy excitations of the heavy-fermion superconductor PrOsSb

Kuwahara, Keitaro*; Iwasa, Kazuaki*; Kogi, Masafumi*; Kaneko, Koji; Metoki, Naoto; Raymond, S.*; Masson, M.-A.*; Flouquet, J.*; Sugawara, Hitoshi*; Aoki, Yuji*; et al.

Physica B; Condensed Matter, 385-386(Part 1), p.82 - 84, 2006/11

https://doi.org/10.1016/j.physb.2006.05.109

We report inelastic neutron scattering experiments performed to investigate the low energy magnetic excitations on single crystals of the heavy-fermion superconductor PrOsSb. The observed excitation clearly softens at a wave vector Q=(1,0,0), which is the same as the modulation vector of the field-induced antiferro-quadrupolar ordering, and its intensity at Q=(1,0,0) is smaller than that around the zone center. This result directly evidences that this excitonic behavior is derived mainly from nonmagnetic quadrupolar interactions. Furthermore, the narrowing of the linewidths of the excitations below the superconducting transition temperature indicates the close connection between the superconductivity and the excitons.