Inhaltszusammenfassung

The occurrence of superconductivity in a new ternary non-transition element compound with the cubic NaCl structure is reported. The composition of this compound is Ag1?xSn1 xSe2?y, with a maximum homogeneity range given by ?0.02 x0.24 and 0 y 0.1. The superconducting transition temperature (Tc) ranges from a minimum of 4.5 K for x = ?0.02, y = 0 to a maximum of 6.9 K for x = 0.24,y = 0. These Tc's are higher than previously observed in nontransition element NaCl structure compounds. Electr...The occurrence of superconductivity in a new ternary non-transition element compound with the cubic NaCl structure is reported. The composition of this compound is Ag1?xSn1 xSe2?y, with a maximum homogeneity range given by ?0.02 x0.24 and 0 y 0.1. The superconducting transition temperature (Tc) ranges from a minimum of 4.5 K for x = ?0.02, y = 0 to a maximum of 6.9 K for x = 0.24,y = 0. These Tc's are higher than previously observed in nontransition element NaCl structure compounds. Electrical resistivity data show a positive temperature coefficient, and room temperature magnetic susceptibility measurements reveal a rapidly increasing density of states at the Fermi level with increasing x. Two ionic models for calculating the carrier concentration of Ag1?xSn1 xSe2?y are discussed, and a third model based on the band picture is proposed. The composition dependence of the magnetic susceptibility was used to test the validity of each of the models. » weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
Physik der kondensierten Materie

DDC Sachgruppe:
Physik