Publikationen

Diffusion jumps of single atoms into vacancies in an iron monolayer studied by nuclear resonant scattering

Autor(en)

Gero Vogl, Ewa Partyka-Jankowska, A Chumakov, Marcin Zajac

Abstrakt

We study the structure of a model surface, i.e., an Fe monolayer on W(110) by nuclear resonant scattering

of x rays. We conclude that at room temperature the structure is nearly perfect, whereas when increasing the

temperature up to 770 K an increasing fraction of the Fe atoms feels the appearance of defects manifested by

a beat structure due to an electric field gradient. The field gradient is caused by an asymmetry of the neighborhood

of part of the atoms and attributable to an increasing fraction of vacancies in the monolayer. With

increasing temperature the beat structure gets smeared due to the onset of dynamics in the surface, i.e., the

motion of the defects and consequently of the atoms. From the temperature dependence of the amplitude of the

beat we deduce the vacancy concentration, thus the vacancy formation energy [0.17(5) eV] and from the

broadening with less accuracy we deduce the vacancy migration energy [0.16(6) eV] resulting in 0.33(11) eV

for the activation energy of diffusion.

Organisation(en)

Dynamik Kondensierter Systeme

Externe Organisation(en)

European Synchrotron Radiation Facility ESRF, AGH University of Science and Technology

Journal

Physical Review B

Band

Anzahl der Seiten

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.80.115406

Publikationsdatum

2009

Peer-reviewed

ÖFOS 2012

1030 Physik, Astronomie

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