Crystal-field study in rare-earth-doped semiconducting YBiPt

We report a high-pressure single-crystal study of the non-centrosymmetric superconductor YPtBi (Tc = 0.77 K). Magnetotransport measurements show a weak metallic behavior with a carrier concentration n ≃ 2.2 × 10 19 cm −3 . Resistivity measurements up to p = 2.51 GPa reveal superconductivity is promoted by pressure. The reduced upper critical field Bc2(T ) curves collapse onto a single curve, with values that exceed the model values for spin-singlet superconductivity. The Bc2 data point to an odd-parity component in the superconducting order parameter, in accordance with predictions for non-centrosymmetric superconductors.

show abstract

“…23) and by taking into account that for our sample n at low T is 10× higher than reported in Ref. 1.…”

mentioning

confidence: 58%

Superconductivity in noncentrosymmetric YPtBi under pressure

et al. 2012

View full text Add to dashboard Cite

show abstract

“…(2) The previously reported low-temperature specific heat data for single-crystal samples show broad features above T N , 5 which makes a quantitative determination of the CEF-level scheme difficult. (3) The previous electron spin resonance measurements were made on a small singlecrystal sample of Y 0.9 Yb 0.1 BiPt, 19 and the effects of spinspin correlations on the CEF level scheme may not have been fully realized. In addition, further measurements employing probes more sensitive to local distortions of the lattice, such as x-ray spectroscopy (in particular extended x-ray absorption fine structure), atomic-pair-distribution-function analysis, and Mössbauer spectroscopy, should be made on single-crystal samples.…”

Section: B Thermal Expansion and The Crystalline-electric-field Schemementioning

confidence: 99%

“…For this fit, γ i , A, and the energy of the excited doublet were allowed to vary, and the location of the quartet was taken as E = 0.52 meV, which corresponds to the value obtained from electron spin resonance experiments on Y 0.9 Yb 0.1 BiPt. 19 The solid blue line corresponds to the CEF level scheme given in Ref. 7, which is appropriate for a CEF with lower than cubic symmetry acting on the Yb 3+ ions.…”

Section: B Thermal Expansion and The Crystalline-electric-field Schemementioning

confidence: 99%

“…17,18 Next, specific heat data show that an entropy of S = R ln 2 is recovered by T ≈ 1 K, which indicates that the CEF ground state is likely a doublet, 2 and data from specific heat and electron spin resonance experiments point to the first and second excited levels occurring at E ≈ 0.5 to 1.1 meV and E 7.6 meV, respectively. 5,19 Finally, from magnetic susceptibility data, the ground state was determined to likely be a Γ 7 doublet, 2 and, from inelastic neutron scattering data, the first excited level was predicted to be a Γ 8 quartet. 20 On the other hand, inelastic neutron scattering experiments found a scattering peak at E = 5.7 meV, which was identified as a CEF level transition to an excited doublet, and two inelastic peaks centered at ≈ 1 and 2 meV, which become resolved at T 10 K and lie on top of two broad quasielastic signals.…”

Section: B Thermal Expansion and The Crystalline-electric-field Schemementioning

confidence: 99%

See 1 more Smart Citation

High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

et al. 2015

View full text Add to dashboard Cite

YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below a temperature of T * = 0.7 K, fragile antiferromagnetic order below TN = 0.4 K, a Kondo temperature of TK ≈ 1 K, and crystalline-electric-field splitting on the order of E/kB = 1 -10 K. Whereas the compound has a facecentered-cubic lattice at ambient temperature, certain experimental data, particularly those from studies aimed at determining its crystalline-electric-field scheme, suggest that the lattice distorts at lower temperature. Here, we present results from high-resolution, high-energy x-ray diffraction experiments which show that, within our experimental resolution of ≈ 6 -10 × 10 −5Å , no structural phase transition occurs between T = 1.5 and 50 K. In combination with results from dilatometry measurements, we further show that the compound's thermal expansion has a minimum at ≈ 18 K and a region of negative thermal expansion for 9 T 18 K. Despite diffraction patterns taken at 1.6 K which indicate that the lattice is face-centered cubic and that the Yb resides on a crystallographic site with cubic point symmetry, we demonstrate that the linear thermal expansion may be modeled using crystalline-electric-field level schemes appropriate for Yb 3+ residing on a site with either cubic or less than cubic point symmetry.

show abstract

“…Magnetotransport data taken on single crystals grown from Bi flux show semi-metallic [1,2] or weakmetallic [10] [10], respectively. The low carrier concentration results in a very small value of the Sommerfeld coefficient in the specific heat: γ ≤ 0.1 mJ/molK 2 [19].…”

Section: Previous Work and Motivationmentioning

confidence: 99%

Ballistic transport in one-dimensional random dimer photonic crystals

Cherid

Bentata

Zitouni

et al. 2014

Solid State Communications

View full text Add to dashboard Cite

The low-field magnetic response of the non-centrosymmetric superconductor YPtBi (T c = 0.77 K) is investigated. Ac-susceptibility and dc-magnetization measurements provide solid evidence for bulk superconductivity with a volume fraction of ∼ 70 %. The lower critical field is surprisingly small: B c1 = 0.008 mT (T → 0). Muon spin rotation experiments in a transverse magnetic field of 0.01 T show a weak increase of the Gaussian damping rate σ T F below T c , which yields a London penetration depth λ = 1.6 ± 0.2 µm. The zero-field Kubo-Toyabe relaxation rate σ KT equals 0.129 ± 0.004 µs −1 and does not show a significant change below T c . This puts an upper bound of 0.04 mT on the spontaneous magnetic field associated with a possible odd-parity component in the superconducting order parameter.

show abstract

Crystal-field study in rare-earth-doped semiconducting YBiPt

Cited by 36 publications

References 24 publications

Superconductivity in noncentrosymmetric YPtBi under pressure

Superconductivity in noncentrosymmetric YPtBi under pressure

High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

Ballistic transport in one-dimensional random dimer photonic crystals

Contact Info

Product

Resources

About