The resistivity and plasmon energies of bcc and A-15 superconductors

Measurements have been made of the plasmon energies in Nb, bcc Nb1-yTiyalloys as a function of y, and Nb1-xGexsamples as a function of x. The samples investigated are 1 micron thick film samples synthesized by selectively thermalized trisputtering. Samples of these systems can be synthesized in an amorphous as well as a crystalline state. Measurements of the plasmon energies have been made by electron energy loss spectroscopy. The measurements reported here were made with a primary electron beam energy of 80eV. For pure Nb a plasmon energy of 9.65±0.10eV was measured. For A-15 Nb3Ge a value of 4.91 ± 0.08eV was measured. For Nb3Ge from our resistivity data combined with this plasmon energy we calculate a value ofh\tau\min{ep}\max{-1} = 0.148\pm0.017eV for the electron phonon relaxation time. The intensity of the plasmon peak as a function of x and y was observed to correlate with the high Tccomposition region. Samples have been characterized by Tc, resistivity, X-ray diffraction, X-ray fluorescence, and Auger measurements.