ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Superconductivity in two Li-containing compounds of Li2Pd3B and Li2Pt3B was recentlydiscovered. 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 withoutmirror or inversion symmetry along any directions. This is a very interesting feature of thosematerials in relation to the symmetry of superconductivity. Resistivity measurements in magneticfields gave their upper critical fields, Hc2(0) = 45 kOe and 19 kOe, respectively. Their specific heatwas measured using a heat-pulse relaxation method. The Sommerfeld coefficient (γ) and Debyetemperature (θD) terms of Li2Pd3B were given as γ=9.5 mJmol-1K-2 and θD=228 K . The value of[removed info]C/γT at Tc was calculated to be 1.7. In the same manner, those parameters were described forLi2Pt3B as γ=9.6 mJmol-1K-2, θD=240 K, and [removed info]C/γTc =0.75, respectively. Since [removed info]C/γTC in the weakcouplinglimit by the BCS theory is 1.43, the value of 1.7 for Li2Pd3B is slightly higher. Theelectronic specific heat of Li2Pd3B at a zero magnetic field follows the typical exponetial behaviordiscribed in the BCS theory, while that of Li2Pt3B shows quadratic behavior. This result suggeststhe line nodes exist in the superconducting gap of Li2Pt3B driven by the spin-orbit interaction
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/18/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.561-565.2079.pdf
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