- journal_title：American Mineralogist
- Contributor：Yang Ding ; David R. Veblen ; Charles T. Prewitt
- Publisher：Mineralogical Society of America
- Date：2005-
- Format：text/html
- Language：en
- Identifier：10.2138/am.2005.1518
- journal_abbrev：American Mineralogist
- issn：0003-004X
- volume：90
- issue：8-9
- firstpage：1265
- section：Articles
Based on magnetic structure and TEM studies of bornite we propose a new 2a Fe/Cu ordered superstructure model with symmetry F4̅3m and formula Cu8Fe4S8. First principles calculations (LAPW implemented in WIEN97 code) of two Fe/Cu ordering schemes indicate that, at the ground state, the Fe atoms should fill the tetrahedral sites of sulfur atoms in the anti-fluorite cube, and the vacancies are associated with Cu atoms in the zincblende cube of the superstructure. The calculated magnetic moment of iron in the Fe/Cu-ordered structure is about 4 μβ which was not expected from previous work because bornite has both covalent and metallic bonds that make crystal-field theory inappropriate for explaining the magnetic moment of Fe. High-resolution transmission electron microscopy (HRTEM) image simulations for the newly proposed structure model are much closer to experimental HRTEM images than those for the model proposed by xref-ref-8-1" class="xref-bibr">Kanazawa et al. (1978).