Reassignment of the absorption spectra of purple yoderite |
| |
Authors: | K Langer G Smith U Hålenius |
| |
Institution: | 1. Institut für Mineralogie und Kristallographie, Technische Universit?t, Hardenbergstr. 42, 1000, Berlin 12, Germany 2. Sveriges Geologiska Unders?kning, S 95128, L?lea, Sweden
|
| |
Abstract: | Polarized spectra E∥X, E∥Y, and E∥Z of purple yoderite, taken at 295 and 100 K, result in a revised interpretation for the mineral. Major bands at around 16,900 (X>Y?Z), 18,600 (X?Y), and 20,600 cm?1 (X≈Z>Y) may be attributed to spin-allowed transitions of Mn3+ in trigonal bipyramids (A2 or A3). Minor features may be assigned to single ion Fe3+. However, charge transfer possibilities for bands at 18,600 and 25,500 cm?1 in yoderite cannot be ruled out and are discussed. The extremely high intensity of Mn3+ spin-allowed bands (?, 216 to 1,900 1·g-atom?1·cm?1]) is attributed to fivefold coordination of the A2 and A3 position and to the covalency of the Mn3+-O bonds. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|