Accession Number : ADP007926

Title :   Rotationally Anisotropic Second-Harmonic Generation Studies of the Structure and Thermal Stability of Cu(110),

Corporate Author : LOS ALAMOS NATIONAL LAB NM

Personal Author(s) : Hoffbauer, Mark A. ; Mcveigh, Victoria J. ; Zuerlein, Michael J.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : The microscopic structure and thermal stability of interfaces are of fundamental importance in determining a variety of materials properties. Order-disorder transitions on surfaces have recently received considerable attention in the scientific literature since the dynamics of such processes can impose fundamental limits on material performance at elevated temperatures. Many high-index (11 n) faces (where n>2) of single-crystal metal surfaces are known to undergo this type of phase-transition. By definition, roughening of an atomically clean surface consists of the proliferation of atomic steps by thermal means at a roughening temperature, TR, where the surface free energy for creation of a step becomes zero. An unresolved question of fundamental importance is whether the roughening temperature of a low-index (110) surface can be lower than the bulk crystal melting temperature. For high index faces, a less stringent definition of roughening involving the proliferation of kinks on the already present step rows that can meander randomly has been suggested.

Descriptors :   *COPPER, *THERMAL STABILITY, *SURFACE PROPERTIES, CRYSTALS, DYNAMICS, FREE ENERGY, INTERFACES, MELTING, METALS, SINGLE CRYSTALS, STRUCTURES, SURFACES, TEMPERATURE, TRANSITIONS.

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE