Upper critical fields and high superconducting transition temperatures of La1.85Sr0.15CuO4 and La1.85Ba0.15CuO4

1987 ◽  
Vol 50 (9) ◽  
pp. 543-544 ◽  
Author(s):  
D. W. Capone ◽  
D. G. Hinks ◽  
J. D. Jorgensen ◽  
K. Zhang
Keyword(s):  
Transition Temperatures ◽  
Superconducting Transition ◽  
Critical Fields ◽  
Upper Critical Fields

scholarly journals Anomalous pressure effect on the superconducting transition temperatures and critical fields of Ho1−xYxNi2B2C

2011 ◽  
Vol 273 ◽  
pp. 012082 ◽  
Author(s):  
Gendo Oomi ◽  
Yukio Sakikawa ◽  
Mio Ohmura ◽  
Masashi Ohashi ◽  
P C Canfield ◽  
...  
Keyword(s):  
Pressure Effect ◽  
Transition Temperatures ◽  
Superconducting Transition ◽  
Critical Fields

Superconductivity at Tc = 36.5 K in Na-Substituted SrFe2As2 Single Crystals

2014 ◽  
Vol 95 ◽  
pp. 150-155 ◽  
Author(s):  
Larysa Shlyk ◽  
Markus Bischoff ◽  
Eva Rose ◽  
Rainer Niewa
Keyword(s):  
Single Crystals ◽  
Anisotropy Ratio ◽  
Superconducting Transition ◽  
Critical Fields ◽  
Superconducting Cuprates ◽  
Resistivity Measurements ◽  
Relaxation Measurements ◽  
Narrow Width ◽  
Upper Critical Fields

We report superconductivity, which is achieved in Sr1-xNaxFe2As2 at Tc = 36.5 K for x = 0.47. Single crystals of Na-substituted SrFe2As2 up to 2 × 2 mm2 were grown from NaF flux. The superconducting transition temperature with a narrow width less than 2 K, confirmed by both magnetic and resistivity measurements, indicates the high quality of our samples. The upper critical fields (0) = 87 T and (0) = 217.5 T are extremely high. The anisotropy ratio γ ~ 2.5 is close to that of other hole-or electron-doped 122 phases but lower than γ ~ 4.3 – 5 of phases from the 1111 series and much lower than γ ~ 7 – 10 of superconducting cuprates. Magnetic relaxation measurements, which are consistent with the collective pinning model, reveal that the flux-creep rate in Na substituted 122 SrFe2As2 is smaller than in 1111 type iron pnictides.

Physical Properties of Li2Pd3B and Li2Pt3B Superconductors

2007 ◽  
Vol 561-565 ◽  
pp. 2079-2082 ◽  
Author(s):  
Hiroyuki Takeya ◽  
Shigeru Kasahara ◽  
Mohammed El Massalami ◽  
Takashi Mochiku ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Specific Heat ◽  
Relaxation Method ◽  
Zero Magnetic Field ◽  
Bcs Theory ◽  
Superconducting Gap ◽  
Electronic Specific Heat ◽  
Superconducting Transition ◽  
Critical Fields ◽  
Resistivity Measurements ◽  
Upper Critical Fields

Superconductivity in two Li-containing compounds of Li2Pd3B and Li2Pt3B was recently discovered. These materials, showing the superconducting transition at 7.2 K and 2.6 K, respectively, have the same cubic structure (P4332) composed of distorted octahedrons without mirror or inversion symmetry along any directions. This is a very interesting feature of those materials in relation to the symmetry of superconductivity. Resistivity measurements in magnetic fields gave their upper critical fields, Hc2(0) = 45 kOe and 19 kOe, respectively. Their specific heat was measured using a heat-pulse relaxation method. The Sommerfeld coefficient (γ) and Debye temperature (θD) terms of Li2Pd3B were given as γ=9.5 mJmol-1K-2 and θD=228 K . The value of C/γT at Tc was calculated to be 1.7. In the same manner, those parameters were described for Li2Pt3B as γ=9.6 mJmol-1K-2, θD=240 K, and C/γTc =0.75, respectively. Since C/γTC in the weakcoupling limit by the BCS theory is 1.43, the value of 1.7 for Li2Pd3B is slightly higher. The electronic specific heat of Li2Pd3B at a zero magnetic field follows the typical exponetial behavior discribed in the BCS theory, while that of Li2Pt3B shows quadratic behavior. This result suggests the line nodes exist in the superconducting gap of Li2Pt3B driven by the spin-orbit interaction.

Prediction of phonon-mediated superconductivity in two-dimensional Mo2B2

2019 ◽  
Vol 7 (9) ◽  
pp. 2589-2595 ◽  
Author(s):  
Luo Yan ◽  
Tao Bo ◽  
Peng-Fei Liu ◽  
Bao-Tian Wang ◽  
Yong-Guang Xiao ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Transition Temperatures ◽  
Superconducting Transition ◽  
Molybdenum Boride

We predict two new molybdenum boride monolayers as phonon-mediated superconductors with superconducting transition temperatures of 3.9 and 0.2 K.

A novel technique for synthesizing MgB2thin films with high upper critical fields

2008 ◽  
Vol 21 (8) ◽  
pp. 085009 ◽  
Author(s):  
Y Shen ◽  
R Gandikota ◽  
R K Singh ◽  
F L Hunte ◽  
J Jaroszynski ◽  
...  
Keyword(s):  
Critical Fields ◽  
Novel Technique ◽  
Upper Critical Fields
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