Impurity and doping effects on the pseudoenergy gap in CeNiSn: A Sn NMR study

Nakamura, Kōichi; Kitaoka, Y.; Asayama, Kunisuke; Takabatake, Toshiro; Nakamoto, G.; Tanaka, Hiroaki; Fujii, H.

doi:10.1103/physrevb.53.6385

Cited by 65 publications

(49 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1, 2) located at the Fermi level. Our calculations agree with NMR experiment [30] and always predict the small DOS at F. However, a standard resolution of only 0.4 eV of the measured VB XPS spectra makes discussing of the Kondo-insulator behavior impossible. The spectra are detected at room temperature, while the calculations have been done for the ground state.…”

Section: Electronic Structure Of Cenisn and Cerhsbsupporting

confidence: 77%

Band Gap Stability in Kondo Insulators

2000

View full text Add to dashboard Cite

We report on magnetic measurements and electronic structure investigations of CeNiSn and CeRhSb. Both belong to the group of Kondo insulators. The magnetic susceptibility shows the nonmagnetic ground state for these compounds and their alloys. The 3d X-ray photoemission spectroscopy spectra show evidence for the mixed valence state of Ce in CeRhSb alloys, as also seen for CeNiSn, whereas the spectra for the La substituted (Ce,La)NiSn compounds show only evidence for a pure Ce 3+ ground state. We suggest the presence of Kondo-hole states in (Ce,La)RhSb. The location of the pseudogap in CeRhSb varies with the number of free electron, the valence of Ce, and the f-d hybridization. We discuss the similar crystallographic properties and the closed electronic structures of ZrNiSn-type semi-Heusler alloys and CeNiSn-type Kondo insulators.

show abstract

Section: Electronic Structure Of Cenisn and Cerhsbsupporting

confidence: 77%

Band Gap Stability in Kondo Insulators

2000

View full text Add to dashboard Cite

show abstract

“…In CeRhSb and CeNiSb, which form orthorhombic structures, 1/T 1 is explained by the Vshaped gap model. 22,23 In Ce 3 Bi 4 Pt 3 , which forms a cubic structure, 1/T 1 that decreases exponentially is explained by assuming an isotropic gap model with a rectangular DOS. 24 The difference in the gap structure for the "Kondo" insulators may be related to their crystal structure.…”

Section: ′′mentioning

confidence: 99%

Novel Phase Transition Near the Quantum Critical Point in the Filled-Skutterudite Compound CeOs₄Sb₁₂: An Sb-NQR Study

et al. 2005

Self Cite

View full text Add to dashboard Cite

We report on a novel phase transition at T = 0.9 K in the Ce-based filled-skutterudite compound CeOs4Sb12 via measurements of the nuclear-spin lattice relaxation rate 1/T1 and nuclear quadrupole resonance (NQR) spectrum of Sb nuclei. The temperature (T ) dependence of 1/T1 behaves as if approaching closely an antiferromagnetic (AFM) quantum critical point (QCP), following the relation 1/T1 ∝ T /(T − TN) 1/2 with TN = 0.06 K in the range of T = 1.3 − 25 K. The onset of either the spin-density-wave (SDW) or charge-density-wave (CDW) order at T0 = 0.9 K, that is, of the first order, is evidenced by a broadening of the NQR spectrum and a marked reduction in 1/T1 just below T0. The f -electron-derived correlated band realized in CeOs4Sb12 is demonstrated to give rise to the novel phase transition on the verge of AFM QCP.KEYWORDS: filled skutterudite, Kondo semiconductor, quantum critical point, SDW/CDW, NQR, CeOs4Sb12Filled-skutterudite compounds ReT 4 Pn 12 (Re = rare earth; T = Fe, Ru or Os; Pn = P, As or Sb) have attracted much attention because of their rich physical phenomena that are not yet fully understood. For instance, PrFe 4 P 12 shows a heavy fermion (HF)-like behavior with a large mass of m * ∼ 70 m e under a magnetic field (H) 1 and undergoes an anomalous transition at a temperature T = 6.4 K at H = 0, indicative of a quadrupolar ordering. [2][3][4] Note that the large C/T value for this compound is due not only to low-energy degrees of freedom such as either magnetic or quadrupolar fluctuations, but also to the Schottky anomaly originating from some low-lying CEF splitting. PrOs 4 Sb 12 is the first Pr-based HF superconductor to reveal the large jump in the specific heat at T c = 1.85 K, the slope of the upper critical field near T c , and the electronic specific heat coefficient γ ∼ 350 − 500 mJ/K 2 mol in the normal state. 5 The CEF-energy scheme of PrOs 4 Sb 12 has recently been determined to be the singlet Γ 1 ground state accompanying the very low lying excited state Γ (2) 4 , 6, 7 and it was suggested that the HF-like behavior exhibited by PrOs 4 Sb 12 may be relevant to a very close energy level between Γ 1 and Γ 4 . Thus, in the Pr-based compound, the 4f 2 -derived CEF effect plays an important role in their rich physical phenomena.In contrast, most Ce-based filled-skutterudite compounds show semiconducting behavior, on the basis of which they are called hybridization-gap semiconductors. A series of CeT 4 P 12 (T = Fe, Ru or Os) compounds have a hybridization gap of 400∼1500 K, and *

show abstract

“…NMR data [14] and resistivity data indicate gap closure for x ~ 0.1. At this doping level the unit cell volume increase corresponds to the increase for CePt0.2Ni0.8Sn where the gap is also just closed.…”

Section: Cecuxnil_xsn (X =005 01 02)mentioning

confidence: 99%

The competition between kondo and RKKY interaction in CeTSn compounds

Kratzer

1997

Appl. Magn. Reson.

View full text Add to dashboard Cite

This article reviews our investigations of the series CeTSn where T stands for a transition element. Our research was stimulated by the unusual behavior of CeNiSn. These compounds are close to the border between magnetic and nonmagnetic Kondo systems. For the understanding of their physical properties a detailed knowledge of the magnetic properties is essential, laSR experiments allow one to reveal even weak magnetic correlations. Special attention is given to the explanation of experimental details. Pulsed (ISIS) and continuous (TRIUMF) muon beams were used as complementary techniques. Experiments in zero and longitudinal (with respect to the muon spin) applied field allowed the determination of the static width of the magnetic field distribution seen by the muons due to ionic moments as wel! as the fluctuation rate of the internal field. As a part of our experiments, the muon site has been determined and the procedure for this will be described.

show abstract

Impurity and doping effects on the pseudoenergy gap in CeNiSn: A Sn NMR study

Cited by 65 publications

References 32 publications

Band Gap Stability in Kondo Insulators

Band Gap Stability in Kondo Insulators

Novel Phase Transition Near the Quantum Critical Point in the Filled-Skutterudite Compound CeOs₄Sb₁₂: An Sb-NQR Study

The competition between kondo and RKKY interaction in CeTSn compounds

Contact Info

Product

Resources

About

Impurity and doping effects on the pseudoenergy gap in CeNiSn: A Sn NMR study

Cited by 65 publications

References 32 publications

Band Gap Stability in Kondo Insulators

Band Gap Stability in Kondo Insulators

Novel Phase Transition Near the Quantum Critical Point in the Filled-Skutterudite Compound CeOs4Sb12: An Sb-NQR Study

The competition between kondo and RKKY interaction in CeTSn compounds

Contact Info

Product

Resources

About

Novel Phase Transition Near the Quantum Critical Point in the Filled-Skutterudite Compound CeOs₄Sb₁₂: An Sb-NQR Study