Order Parameter of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>MgB</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>: A Fully Gapped Superconductor

Yang, Huanxing; Lin, Jiunn‐Yuan; Li, H. H.; Hsu, F. H.; Liu, C. J.; Li, Shao‐Chun; Yu, Richeng; Jin, Changqing

doi:10.1103/physrevlett.87.167003

Cited by 149 publications

(27 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The more interesting feature appears to be the low temperature shoulder in the excess of specific heat seen in (C p (H = 0) − C p (9T ))/T data below 10 K (also clearly seen for both samples in the previous figure). A similar feature was observed in pure MgB 2 by different groups [24,25,26] and was interpreted as experimental evidence of a second, much lower energy, superconducting gap in MgB 2 [24,25,26,28]. There are other important similarities between heat capacity data of pure magnesium diboride and the carbon doped sample: the low temperature feature disappears (lower gap is quenched) in small (0.5 T) applied field and the ∆C p /γT c value is substantially smaller than expected for a BCS superconductors.…”

Section: Physical Propertiessupporting

confidence: 80%

“…The specific heat jump at the superconducting transition is clearly seen (Fig. 11, inset) and the value of the jump is estimated as ∆C ≈ 23 mJ/mol K. From 9 T measurements the electronic term in specific heat is extrapolated to γ ≈ 1.9 mJ/mol K 2 and the Debye temperature is estimated as Θ D ≈ 685 K. Both γ and Θ D values are lower than those accepted in the literature for pure MgB 2 samples [3,24,25,26] and have the same trend as seen experimentally in [20] and theoretically in [27]. At a gross level, the significant decrease in T c is consistent with lower γ and Θ D values for the carbon doped sample.…”

Section: Physical Propertiesmentioning

confidence: 83%

See 1 more Smart Citation

Carbon doping of superconducting magnesium diboride

Ribeiro

Bud’ko

Petrović

et al. 2003

Physica C: Superconductivity

175

156

View full text Add to dashboard Cite

We present details of synthesis optimization and physical properties of nearly single phase carbon doped MgB 2 with a nominal stoichiometry of Mg(B 0.8 C 0.2 ) 2 synthesized from magnesium and boron carbide (B 4 C) as starting materials. The superconducting transition temperature is ≈ 22 K (≈ 17 K lower than in pure MgB 2 ). The temperature dependence of the upper critical field is steeper than in pure MgB 2 with H c2 (10K) ≈ 9 T. Temperature dependent specific heat data taken in different applied magnetic fields suggest that the two-gap nature of superconductivity is still preserved for carbon doped MgB 2 even with such a heavily suppressed transition temperature. In addition, the anisotropy ratio of the upper critical field for T /T c ≈ 2 3 is γ ≈ 2. This value is distinct from 1 (isotropic) and also distinct from 6 (the value found for pure MgB 2 ).

show abstract

Section: Physical Propertiessupporting

confidence: 80%

Section: Physical Propertiesmentioning

confidence: 83%

Carbon doping of superconducting magnesium diboride

Ribeiro

Bud’ko

Petrović

et al. 2003

Physica C: Superconductivity

175

156

View full text Add to dashboard Cite

show abstract

“…3(f). A nonlinear dependence of γ N (H) on the magnetic field has been argued to be intrinsic property of the multi-band, multi-gap superconductors 25 . This analysis also suggests the presence of multiple gaps at the Fermi level in the superconducting state and indicate multi-band superconductivity in Lu 3 Os 4 Ge 13 single crystal.…”

Section: Resultsmentioning

confidence: 99%

Multiband superconductivity in Lu₃Os₄Ge₁₃

Prakash¹,

Thamizhavel²,

Ramakrishnan³

2015

Supercond. Sci. Technol.

View full text Add to dashboard Cite

Intermetallic R3T4X13 series consists of cage like structure and have been in focus due to their unconventional electronic ground states. In this work, we report the normal and superconducting state properties of a high quality single crystal of Lu3Os4Ge13. Lu3Os4Ge13 belongs to the above mentioned series and crystallizes in a cubic crystal structure with the space group Pm3 n. Using electrical transport, magnetization and heat capacity measurements, we show that Lu3Os4Ge13 is a type-II multi-band superconductor (T c = 3.1 K) with unusual superconducting properties. The analysis of the low temperature heat capacity data suggests that Lu3Os4Ge13 is a moderately coupled multi-band BCS superconductor with two gaps (2∆/kBT c = 3.68 ± 0.04 & 0.34 ± 0.02) in the superconducting state. The dc-magnetization (M − H) shows a large reversible region in the superconducting state similar to the vortex liquid phase observed in high-T c superconductors. The value of the Ginzburg number Gi suggests that the thermal fluctuations, though small as compared to those in high-T c cuprates, may play an important role in the unpinning of the vortices in this compound. The electronic band structure calculations show that three bands cross the Fermi level and constitute a complex Fermi surface in Lu3Os4Ge13.

show abstract

“…The difference of preparation between two samples was the amount of bromine (Br 2 ) used in soft-chemical processes with chemical oxidation. Heat-pulse thermal relaxation calorimetry [3] was used to take low-temperature specific-heat data down to 0.6 K without and with magnetic field up to 8 T. In Fig. 1, the solid line is the normal state fitting deduced from the 8 T data by using C n ¼ g n +C lattice (T), where g n T is the electronic term due to free charge carriers and C lattice (T) ¼ bT 3 +aT 5 represents the phonon contribution.…”

Section: Resultsmentioning

confidence: 99%