Book/Report

FZJ-2018-03135

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Phasenübergänge in Systemen mit reduzierter Dimensionalität

Dürr, W. (Corresponding author)FZJ*

1989
Kernforschungsanlage Jülich, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/18643

Report No.: Juel-2287

Abstract: Using spinpolarized low energy electron diffraction (SPLEED), two types of phase transitions have been investigated: The magnetic phase transition of truly two-dimensional Fe-films on Au(100) and the melting of the (110)-surface of Pb. Ultrathin Fe-films on Au(100) show following properties: 1) All films including the one monolayer are ferromagnetic and have a sharp 2nd order phase transition at a thickness dependent Curie temperature. 2) Their magnetization M disappears at the Curie temperature T$_{c}$ according to a power law M $\thicksim$ (1-T/T$_{c})^{\beta}$ with $\beta$ = 0,22 $\pm$ 0,02. 3) These Fe-films are truly two-dimensional systems and obey the universality hypothesis, i. e. $\beta$ is independent of the strength of the magnetic interaction. The investigations of the (110)-surface of Pb led to following results: 1) By a proper choice of scattering geometry, surface order-disorder phase transitions can be accessed by spinpolarized diffraction techniques. 2) The (110)-surface of Pb melts at 527 $\pm$ 3 K, i. e. well below the bulk melting temperature of 600,7 K. 3) Surface melting is a 1st order phase transition as in the bulk.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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