EXAFS- and XANES-like spectra obtained by x-ray-excited scanning tunnelingmicroscope tip current measurement

As reported previously the tip current of a scanning tunneling microscope ( STM) is excited by irradiation of x-rays on the sample. This x-ray-excited STM tip current originates from electrons emitted from the sample surface, We measured the STM tip current excited by synchrotron radiation for Au-Ni thin-film samples as the x-ray energy was scanned near the Au L III and Ni K absorption edges It Has found that the STM tip current increased at the x -ray energy near the absorption edge and extended x-ray adsorption fine str ucture (EXAFS)-like and x-ray adsorption near-edge structure (XANES)-like s pectra were obtained, The experimental result using the tip coated with ins ulator suggested that the analysing area was similar to 1.0 mm in diameter. Copyright (C) 1999 John Wiley & Sons, Ltd.