Accession Number : AD0709985

Title :   FIELD ION MICROSCOPY

Descriptive Note : Final rept. 1 Jun 1969-31 May 1970

Corporate Author : PENNSYLVANIA STATE UNIV STATE COLLEGE FIELD EMISSION LAB

Personal Author(s) : Mueller, Erwin W

PDF Url : AD0709985

Report Date : 03 Aug 1970

Pagination or Media Count : 13

Abstract : The basic physical effects used in field ion microscopy are not yet fully understood. Field evaporation rates of tungsten were measured in the range from 0.01 to 10,000,000 atomic layers/sec, yielding the polarizability of a kink site surface atom, the activation energy and the pre-exponential of the field evaporation equation. Using the polarizability, the dipole-dipole binding energy of field-adsorbed noble gases ahs been calculated, and a modified mechanism of field ionization and image interpretation is proposed. A high-voltage field ion microscope has been operated at up to 45 kV, giving an increased field of view.

Descriptors :   *MICROSCOPY, *TUNGSTEN, IONIZATION POTENTIALS, IONS, POLARIZATION, SURFACE PROPERTIES

Subject Categories : Physical Chemistry
      Test Facilities, Equipment and Methods
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE