AVS 52nd International Symposium
    Surface Science Friday Sessions
       Session SS2-FrM

Invited Paper SS2-FrM3
Phase Diagram of Cr110 Thin Films Measured by ARPES

Friday, November 4, 2005, 9:00 am, Room 203

Session: Electronic Structure of Surfaces
Presenter: E. Rotenberg, Lawrence Berkeley National Laboratory
Authors: E. Rotenberg, Lawrence Berkeley National Laboratory
B.K. Freelon, Lawrence Berkeley National Laboratory
S.A. Morton, Lawrence Berkeley National Laboratory
H. Koh, Lawrence Berkeley National Laboratory
A. Bostwick, Lawrence Berkeley National Laboratory
K. Rossnagel, Univ. Kiel, Germany
A.K. Schmid, Lawrence Berkeley National Laboratory
S.D. Kevan, Univ. of Oregon
Correspondent: Click to Email
We report the impact of dimensional confinement on physical properties associated with the spin-density wave (SDW) ground state in chromium. These properties are also of some technological importance since chromium is a common component of thin film magnetic structures. We prepared chromium (110) films of high crystalline quality on a W(110) substrate with a wedge-shaped thickness profile so that the impact of confinement can be systematically studied. We have characterized these films using a combination of low-energy electron diffraction and microscopy as well as high-resolution angle-resolved photoemission spectroscopy. By probing the Fermi surface and the nesting vectors that are relevant to the SDW ground state, we characterized the SDW incommensurability in the film directly, and we find that this incommensurability deviates markedly from the bulk value for thin films at higher temperatures: we find commensurate and incommensurate phases that are separated by nearly continuous transitions. Further changes in the SDW phase diagram arise upon hydrogen adsorbtion. Our results suggest a simple model to explain the delicate interplay between commensurate and incommensurate phases that involves a balance between SDW stabilization energy and surface and interface energetics.