THE CHANGE FROM QUASI-ONE-DIMENSIONAL TO 3-DIMENSIONAL METALLIC BEHAVIOR - THEORETICAL AND EXPERIMENTAL ELECTRONIC BAND STRUCTURES AND ELECTRICAL-PROPERTIES OF NB3TE4 AND NB3TE3AS

A detailed study of the electronic structure of Nb3Te4-xAsx for x = 0, 0.5 and 1.0 using core level X-ray photoelectron spectroscopy and val ence band. ultraviolet photoelectron spectroscopy is presented. Using He I and He II radiation, pronounced changes in the spectra upon repla cing Te by As are found in the region close to the Fermi energy. These changes are explained on the basis of the electronic band structure c alculations using the linear muffin tin orbital method. In addition, t hese calculations clearly demonstrate the change from quasi-one- to th ree-dimensional behavior upon going from Nb3Te4 to Nb3Te3As. This is i n line with results of resistivity measurements presented, as well as previous X-ray single crystal investigations, Down to 1.5 K no transit ion into the superconducting state is observed.