Direct observation of atomic exchange during surface self-diffusion

Author

Matthew Aaron Koppa, University of New MexicoFollow

Publication Date

Fall 12-14-2019

Abstract

The diffusion of adatoms across the (100) plane of iridium has been previously inferred to occur by an exchange mechanism based on site mapping. This study provides the first direct observation that surface self-diffusion can occur by exchange. Iridium enriched to ≥93% ¹⁹¹Ir was deposited onto an atomically clean and smooth Ir(100) plane as observed in an atom probe field ion microscope. Following thermally activated surface self-diffusion the adatom was field desorbed and mass analyzed. Observation of the ¹⁹³Ir isotope in one-half of the cases demonstrates conclusively that atomic exchange can occur during surface self-diffusion.

Degree Name

Physics

Level of Degree

Doctoral

Department Name

Physics & Astronomy

First Committee Member (Chair)

Paul R. Schwoebel

Second Committee Member

David H. Dunlap

Third Committee Member

Wolfgang Rudolph

Fourth Committee Member

John Grey

Fifth Committee Member

John A. Panitz

Language

English

Keywords

Surface diffusion, surface physics, field ion microscopy

Document Type

Dissertation

Recommended Citation

Koppa, Matthew Aaron. "Direct observation of atomic exchange during surface self-diffusion." (2019). https://digitalrepository.unm.edu/phyc_etds/226