Progress towards spin-polarized scanning tunneling microscopy

Abstract

Solutions to the main problems in operating a spin?polarized scanning tunneling microscope are discussed. Preliminary experimental results obtained in the course of implementing these solutions are reported. Atomic resolution on Si(111) and Si(100) is achieved with a scanning tunneling microscope (STM) using chromium and iron tips. Fabrication of antiferromagnetic tips of Cr, MnNi, and MnPt is described. A technique of preparation of clean (100) surfaces of Fe3O4 (magnetite) is given. Low?energy electron diffraction patterns were obtained on Fe3O4 for the first time. The first STM experimental results obtained on magnetite in air and in ultrahigh vacuum are reported. Atomic resolution is obtained on Fe3O4 (100) with an ultrahigh vacuum scanning tunneling microscope using iron and tungsten tips. This is the first successful observation of atomic resolution on a ferromagnetic sample using a ferromagnetic tip.