Accession Number : AD0709985

Title :   FIELD ION MICROSCOPY.

Descriptive Note : Final rept. 1 Jun 69-31 May 70,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK FIELD EMISSION LAB

Personal Author(s) : Mueller,Erwin W.

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. (Author)

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

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

Distribution Statement : APPROVED FOR PUBLIC RELEASE