Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
We report results on a new class of superconducting (SC) materials, In doped Sn1-xPbxTe solid solutions. The interest in this system is stimulated by the unique properties of indium that creates a resonance band in the valence band of Sn1-xPbxTe. The high density of states in the resonance band stabilizes the Fermi level, which is responsible for spatial homogeneity. These materials exhibit SC transition with abnormally high critical temperature Tc for semiconductors. We carried out the magnetic susceptibility (Maxwell bridge) and resistivity (four-point probe) measurements from room temperature down to 1.5 K, on polycrystalline samples with an average grain size of 200mm. The simultaneous measurements show the bulk character of the SC transition with the resistivity transition leading the transition in magnetic susceptibility. In spite of the high homogeneity of these materials, the SC transition in resistivity can happen along the crystallites’ surfaces. The correlation in the temperature dependence of resistivity and magnetic susceptibility with almost zero slope at low temperatures above Tc, shows the dominance of impurity scattering into the resonance band, which is known to be important for occurrence SC transition in these materials.