AN ELECTRON ENERGY LOSS AND ULTRAVIOLET PHOTOEMISSION STUDY OF VANADIUM-NITRIDE(X), NIOBIUM-NITRIDE(X), AND ZIRCONIUM-NITRIDE(X).

摘要

The techniques of reflection electron energy loss (ELS) and angle-integrated ultraviolet photoemission (UPS) spectroscopies have been used to study the electronic structure and the collective electron behavior of the superconducting transition metal nitrides VN(,x), NbN(,x), and ZrN(,x). When possible, samples have been fabricated within the ultrahigh vacuum surface analysis chamber to insure the highest possible surface cleanliness. Some samples have also been fabricated externally. All samples were further characterized through Auger analysis (in situ), x-ray diffraction, and superconducting transition temperature measurements. ELS was used to study the collective electron (plasmon) and single electron (interband) excitations. UPS was used to probe the occupied valence band density of states. The experimental techniques and underlying theories are discussed. Results are presented and discussed for both the nitrides and the parent transition metals.