METASTABLE DEEXCITATION SPECTROSCOPY: A NEW PROBE OF SURFACE MAGNETISM
ONELLION, MARSHALL FRANKLIN
Doctor of Philosophy
A new method, described herein, has been developed for probing magnetic and other spin-dependent surface properties. The technique utilizes a He 2 ('3)S(,1) beam in which a plurality of atoms is in one m(,J) level. This electron spin polarized beam has been used to probe the surface magnetic properties of a clean and adsorbate-covered Ni (110) crystal. The electrons ejected from the sample when the metastables deexcite depend upon metastable polarization and sample magnetization. By examining the ejected electrons, the sample magnetization has been measured as a function of electron energy, crystal temperature, and adsorbate (CO) coverage. The results demonstrate that He 2 ('3)S(,1) metastables constitute a method for probing surface magnetism with unparalleled surface specificity. In addition to discussing the physics of the metastable/surface interaction and the results obtained, the theoretical background and a perspective of surface spectroscopies are provided in sections on magnetism and other surface spectroscopies.
Condensed matter physics