The optical spectroscopic comparison of the ferric iron tetrameric clusters in amarantite and leucophosphite
Creators
Abstract
Optical absorption spectra and magnetic susceptibility data are presented for two minerals amarantite, Fe_2(SO_4)_2O·7H_2O, and leucophosphite, K_2[Fe_4(OH)_2(H2O)_2(PO_4)_4]·2H_2O, which contam nearly planar ferric iron tetrameric units. These data are compared to corresponding single crystal optical data for phosphosiderite, FePO_4•.2H_2O. Pronounced enhancement of the intensities of the absorption bands and absorption anisotropy, which are associated with the strong antiferromagnetic coupling (µ_(Fe) = 2.53 B.M. at 297°K) of the oxobridged amarantite tetramer, is noted for amarantite. Synthetic leucophosphite exhibits a much weaker antiferro-magnetic interaction (µ_(Fe) = 5.13 B.M.). Natural leucophosphite displays little optical absorption anisotropy and much lower absorption intensity than amarantite.
Additional Information
© 1976 Mineralogical Society of America. Manuscript received, August 15, 1975; accepted for publication, February 25, 1976. Professor Paul B. Moore of the University of Chicago furnished the leucophosphite crystals from the Tip Top pegmatite. The amarantite was obtained from the National Museum of Natural History, Smithsonian Institution.Additional details
Identifiers
- Eprint ID
- 38445
- Resolver ID
- CaltechAUTHORS:20130513-104749141
Dates
- Created
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2013-05-13Created from EPrint's datestamp field
- Updated
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2019-11-26Created from EPrint's last_modified field
Caltech Custom Metadata
- Caltech groups
- Division of Geological and Planetary Sciences (GPS)
- Other Numbering System Name
- Caltech Division of Geological and Planetary Sciences
- Other Numbering System Identifier
- 2512