The magnetic properties of the oxygen–hole aluminum centers in crystalline SiO2. III. [AlO4]+
| Autor: | R. H. D. Nuttall, J. A. Weil |
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| Rok vydání: | 1981 |
| Předmět: | |
| Zdroj: | Canadian Journal of Physics. 59:1886-1892 |
| ISSN: | 1208-6045 0008-4204 |
| DOI: | 10.1139/p81-249 |
| Popis: | The EPR spectra of [AlO4]+ have been measured in α-quartz at ca. 35 K after X-irradiation at 77 K. This center is believed to contain two electron holes, one at each of two symmetry-related oxygen ions bonded to an aluminum ion substituted for silicon, forming a triplet spin system. Measurements of the two primary 27Al hyperfine multiplets (Ms = 0 ↔ Ms = ± 1) as well as the quasi-forbidden multiplet (Ms = + 1 ↔ Ms = −1) at half field have been made, and have led to a spin-Hamiltonian (matrices [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]). A crystal two-fold axis contains the aluminum ion and relates the two-hole-bearing oxygen ions, as well as the two outer silicon ions bonded respectively to the latter. The electronic quadrupole matrix [Formula: see text] is attributed primarily to the magnetic dipole–dipole interaction between the two unpaired electrons. The results of a comparison among the matrices [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and the corresponding matrices for the related single-hole centers [AlO4]0 and [AlO4/M+]+ (where M = H, Li) are consistent with the model for [AlO4]+. |
| Databáze: | OpenAIRE |
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