Direct surface magnetometry with photoemission magnetic x-ray dichroism

Technical Report · Tue Apr 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/603505· OSTI ID:603505

Tobin, J. G.; Goodman, K. W. ^[1]; Schumann, F. O. ^[2]

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1. Lawrence Berkeley National Lab., CA (United States)
2. Pennsylvania State Univ., University Park, PA (United States); and others

Element specific surface magnetometry remains a central goal of synchrotron radiation based studies of nanomagnetic structures. One appealing possibility is the combination of x-ray absorption dichroism measurements and the theoretical framework provided by the {open_quotes}sum rules.{close_quotes} Unfortunately, sum rule analysis are hampered by several limitations including delocalization of the final state, multi-electronic phenomena and the presence of surface dipoles. An alternative experiment, Magnetic X-Ray Dichroism in Photoelectron Spectroscopy, holds out promise based upon its elemental specificity, surface sensitivity and high resolution. Computational simulations by Tamura et al. demonstrated the relationship between exchange and spin orbit splittings and experimental data of linear and circular dichroisms. Now the authors have developed an analytical framework which allows for the direct extraction of core level exchange splittings from circular and linear dichroic photoemission data. By extending a model initially proposed by Venus, it is possible to show a linear relation between normalized dichroism peaks in the experimental data and the underlying exchange splitting. Since it is reasonable to expect that exchange splittings and magnetic moments track together, this measurement thus becomes a powerful new tool for direct surface magnetometry, without recourse to time consuming and difficult spectral simulations. The theoretical derivation will be supported by high resolution linear and circular dichroism data collected at the Spectromicroscopy Facility of the Advanced Light Source.

• Research Organization: Lawrence Berkeley Lab., CA (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 603505
• Report Number(s): LBNL--39981; ON: DE97007345
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DICHROISM
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MEASURING METHODS
PHOTOEMISSION
SOFT X RADIATION
SURFACE PROPERTIES