Bulk band gaps in divalent hexaborides
Complementary angle-resolved photoemission and bulk-sensitive k-resolved resonant inelastic x-ray scattering of divalent hexaborides reveal a >1 eV X-point gap between the valence and conduction bands, in contradiction to the band overlap assumed in several models of their novel ferromagnetism. This semiconducting gap implies that carriers detected in transport measurements arise from defects, and the measured location of the bulk Fermi level at the bottom of the conduction band implicates boron vacancies as the origin of the excess electrons. The measured band structure and X-point gap in CaB6 additionally provide a stringent test case for proper inclusion of many-body effects in quasi-particle band calculations.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of Basic Energy Sciences. Materials Science and Engineering Division, U. of Michigan DE-FG02-90ER45416, Ames Lab W-7405-ENG-82; National Science Foundation Grants DMR-99-71611 and DMR-00-84402 (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 826096
- Report Number(s):
- LBNL-51259; PRLTAO; R&D Project: A580SS; TRN: US0402996
- Journal Information:
- Physical Review Letters, Vol. 89, Issue 15; Other Information: Journal Publication Date: 10/07/2002; PBD: 1 Aug 2002; ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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