Isochromat spectroscopy of photons emitted from metal surfaces in an STM

The pronounced variation of the intensity of photons emitted from the tunneling gap of an STM with respect to the applied bias voltage V_t is studied experimentally using simultaneous measurements of tunneling characteristics and photon emission. We show that the structure in isochromat photon spectra are determined by the following: bias-dependent changes in tunneling characteristics, density of initial and final states, and modifications of tip-induced plasmon modes. It is demonstrated that isochromat spectra provide a conclusive test for the inelastic tunneling mechanism. Coupling between tunneling electrons and tip-induced plasmon modes which gives rise to the intense photon emission observed is discussed within this model.     

Mach-shock electron distributions from solids

Heavy ion induced density fluctuations in the electron plasma of solids known as wakes show the characteristic features of Mach-shock waves. We propose a method to detect the electron wake in solid state materials by measuring the angular distribution of emitted electrons of low energy. These show up as distinct maxima at certain angles. In the emission angle we find an increase with bombarding energy, following the Mach relation cosΘ _em=v _s /v ₀.     

ET-AAS determination of traces of As, Sb and Sn in pure gold after matrix separation with hydrazine

Summary The possibilities of ET-AAS using the graphite furnace or the tungsten coil atomizer were compared by the trace As, Sb and Sn determination in the chloride-containing solution resulting after gold reduction with hydrazine. It was found that the tungsten coil atomizer tolerates higher concentrations of chloride ions than the conventional graphite furnace.