Temperature-dependent absorption of biotite: small-pola
- journal_title：European Journal of Mineralogy
- Contributor：Claus H. Rüscher
- Publisher：E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
- Date：2012-
- Format：text/html
- Language：en
- Identifier：10.1127/0935-1221/2012/0024-2200
- journal_abbrev：Eur J Mineral
- issn：0935-1221
- volume：24
- issue：5
- firstpage：817
- section：Articles
摘要
Temperature-dependent absorption investigations between 10 and 823 K reveal photon-assisted hopping (PAH) of small polarons in biotites as the dominating excitation in the near-infrared spectral range. These data show a transfer of oscillator strength of the PAH of small polarons to Fe2+–Fe3+ intervalence-charge transfer and Fe2+ d–d transitions with decreasing temperature. The loss in oscillator strength of PAH is related to a pinning of the polarons due to the decreasing number in lattice vibrations in thermal equilibrium.