Jy. Chan et Sm. Kauzlarich, RARE-EARTH-HALIDES AS FLUXES FOR THE SYNTHESIS OF TANTALUM AND NIOBIUM CARBIDE, Chemistry of materials, 9(2), 1997, pp. 531-534
While investigating the reported superconducting phase of Lu2Cl2C2-x,
we discovered a novel synthetic route for making TaC and NbC. TaC and
NbC are superconducting refractory carbides with a T-c of 10 and 12 K,
respectively. TaC or NbC was initially found as impurity in reactions
designed to produce Lu2Cl2C2-x. TaC and NbC can be prepared as single
crystals by reacting Ta or Nb and C in a LnCl(3) (Ln = Y, Lu) flux at
as low of a temperature as 850 degrees C for 4 days. The products are
characterized by powder X-ray diffraction and magnetic susceptibility
. The various conditions for the preparation of the refractory carbide
s in rare-earth fluxes and their properties will be presented and disc
ussed.