E. Corenzwit

Superconductivity of ternary sulfides and the structure of PbMo6S8

The compound Pb0.92Mo6S7.5, a derivation from the ideal stoichiometric compound PbMo6S8, is a member of the ternary sulfide series MXMo3S4 where M = Ag, Sn, Ca, Sr, Pb, Ba, Cd, Zn, Mg, Cu, Mn, Cr, Fe, Co, Ni, Li, Na, Sc, and Y. Members of the series with M = Pb, Sn, Ag, Cu, Zn, Mg, Cd, Sc and Y have been found to be superconducting at TC = 15.2, 14.2, 9.1, 10.9, 3.6, 3.5, 3.5, 3.6 and 3.0oK respectively. The lead compound has rhombohedral symmetry R3, lattice parameters a = 6.551A and α = 89.33°, and one formula per unit cell. The structure consists of a distorted primitive-cubic network of sulfur atoms with every fourth sulfur cube occupied by either a Pb atom or a Mo6 octahedron. The vertices of the Mo6 octahedron lie in the face centers of the sulfur cube which is tilted approximately 15o with respect to the rhombohedral axes. This arrangement yields open channels running through the structure parallel to the unit cell edges.

Magnetic Ordering in the Rare-Earth Hexaborides

Magnetic ordering in the rare-earth hexaborides has been studied by a variety of methods, and a clear correlation with the presence of conduction electrons has been found.

Superconductivity of Double Chalcogenides: Lix Ti1.1S2.

Lithium titanium sulfides, LixTi1.1S2(0.1 x ≤ 0.3), become superconducting over the temperature range from 10� to 13�K. They have the hexagonal Ti3S4 structure and should not be considered intercalation compounds. This is the first class of noncubic compounds with high transition temperatures.

Superconductivity of some binary and ternary transition-metal borides

Abstract Superconducting transition temperatures of some binary transition-metal borides and a new series of ternary transition-metal borides are reported. The variation of T C vs electron/atom ratio and the crystal chemical behavior of the borides in relation to their superconducting behavior are discussed.

Tetragonal ternary borides: Superconductivity, ferromagnetism and the role of scandium

Abstract We report and discuss two discoveries made while studying the condensation phenomena of ternary rhodium borides, MRh 4 B 4 . M is generally a trivalent transition metal, usually a rare earth element RE. An exception is scandium which by itself does not form an isomorphous boride, but in combination with many other elements will do just that. A surprising correlation between ferromagnetic and superconducting transition temperatures has been found.