PLASMOCHEMICAL SYNTHESIS AND PROPERTIES OF ULTRADISPERSED NIOBIUM NITRIDE

Niobium nitride synthesis by reduction or nitridation of NbF5 in a mic rowave-discharge plasma was studied, and the superconductivity paramet ers of the ultrafine niobium nitride powders obtained were determined. The conditions of the almost complete reduction of NbF5 and the produ ction of single-phase delta-NbN(x) (with a particle size of 28 to 44 n m) were found. The contraction of crystal lattice was observed for the ultrafine powders. It was shown that the critical magnetic field for the ultradispersed niobium nitride is more than 2.5 times higher than that for the monolithic material.