| Autor: |
Boldú O., J. L., Muñoz P., E., Abraham, M. M., Boatner, L. A. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 12/15/1985, Vol. 83 Issue 12, p6113, 8p |
| Abstrakt: |
Divalent manganese has been incorporated in both single crystals and powders of the zircon-structure hosts LuPO4, YPO4, and ScPO4. The single-crystal specimens were grown by slowly cooling a Pb2P2O7 flux from 1360 °C, and finely divided powders of these materials were also prepared using a molten urea precipitation technique. Electron paramagnetic resonance studies have shown that tetragonal symmetry Mn2+ sites are present in both single crystals and powders of ScPO4 and LuPO4 but are not present in either YPO4 single crystals or powders. An orthorhombic symmetry spectrum was observed for Mn2+ in single crystals of all three hosts and in YPO4 powders. Orthorhombic spectra were not found in Mn2+ doped powders of ScPO4 and LuPO4. In the case of the orthorhombic-symmetry spectra, four sites were present in these tetragonal zircon-structure hosts. The sites were magnetically inequivalent but were equivalent in terms of the strength and symmetry of the crystalline electric field. The orientations of the orthorhombic-site principal axes relative to the crystallographic axes were determined in each case. The axial spin-Hamiltonian parameter b02 was found to be positive in the case of the tetragonal-symmetry sites and negative for the orthorhombic-symmetry spectra. Thermoluminescent properties of these materials were also investigated. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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