3d spin-orbit photoemission spectrum of nonferromagnetic materials: The test cases of CoO and Cu
2002 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 66, no 7Article in journal (Refereed) Published
The x-ray photoemission spectrum of the valence states of 3d transition-metal systems is spin polarized when using circularly polarized photons. The integral of the spin-orbit spectrum is proportional to the expectation value of the angular part of the 3d spin-orbit operator in the initial state. We show that this quantity can be used to get an estimate of the atomic orbital moment. While the measurement is sensitive to the magnetization axis, it does not require a net macroscopic magnetization nor the presence of a long-range magnetic order, and is therefore suitable for any transition-metal systems being antiferromagnetic or paramagnetic or magnetically disordered. In the case of full 3d shell the integral of the spin-orbit spectrum is zero, but the spectral shape can give a direct estimate of the 3d spin-orbit energy splitting DeltaE(SO). We have used Cu and CoO to experimentally test this technique. As expected Cu provides a vanishing result for , whereas for Co2+ in CoO we find =1.36h at 0 K. On the other hand we find DeltaE(SO)similar or equal to280 meV for Cu.
Place, publisher, year, edition, pages
2002. Vol. 66, no 7
magnetic circular-dichroism, transition-metal oxides, valence states, cu(111), fe, superconductivity, nanostructures, polarization, au(111), sr2ruo4
IdentifiersURN: urn:nbn:se:kth:diva-21888DOI: 10.1103/PhysRevB.66.075101ISI: 000177969800045OAI: oai:DiVA.org:kth-21888DiVA: diva2:340586
QC 201005252010-08-102010-08-10Bibliographically approved