Laser site-selective spectroscopy of rare-earth ions in crystals of the fluorite structure
| dc.contributor.author | Jamison, Steven P. | en |
| dc.date.accessioned | 2013-08-20T00:19:44Z | |
| dc.date.available | 2013-08-20T00:19:44Z | |
| dc.date.issued | 1998 | en |
| dc.description.abstract | Site-selective laser spectroscopy, Zeeman infrared and optical absorption have been employed to investigate trivalent dysprosium centers in rare-earth doped alkaline-earth fluoride crystals. These studies have characterised the two dominant centers in SrF₂:Dy³⁺ which are determined to be the fluorine compensated C₄ᵥ and C₃ᵥ centers analogous to those observed in other SrF₂:RE³⁺ systems. The C₃ᵥ center is shown to correspond to the J-center of Sr₁:Er³⁺, rather than the B-center reported for SrF₂:Ho³⁺. In CaF₂:Dy³⁺ three single Dy³⁺ ion centers have been characterised, corresponding to the C₄ᵥ , C₃ᵥ and cubic centers. Cluster centers involving more than one Dy³⁺ ion are also present in CaF₂:0.05%Dy³⁺, and such centers undergo efficient non-radiative cross-relaxation. This cross-relaxation eliminates the possibility of a direct investigation of the laser spectroscopy of these cluster centers, leading to the consideration of double doped systems. The laser spectroscopy of CaF₂:Dy³⁺:Eu³⁺ reveals a cluster center with efficient Dy³⁺→’Eu³⁺ energy transfer. Through a correlation of the Eu³⁺ fluorescence with previous studies of CaF₂:Eu³⁺ this center has been determined to be a heterogeneous R-center dimer. The double doped CaF₂:Dy³⁺:Gd³⁺ system has enabled the Dy³⁺ R-center fluorescence to be investigated. The polarised fluorescence of the C₄ᵥ centers in CaF₂:Dy³⁺ and SrF₂:Dy³⁺ has been analysed in terms of both electric dipole and magnetic dipole transition moments, from which it is shown that magnetic dipole processes are significant for Dy³⁺ fluorescence. The temperature dependence of fluorescence polarisation in praseodymium and europium doped CaF₂ and SrF₂ has been employed to investigate ionic motion in the C₄ᵥ centers. These experiments have enabled the barrier energies for interstitial reorientation to be determined in a site-selective manner. An anomalous temperature dependence of the polarisation anisotropy is observed in the Pr³⁺ C₄ᵥ centers, and has been shown to be a consequence of energy transfer between the C₄ᵥ centers. | en |
| dc.identifier.uri | http://hdl.handle.net/10092/8172 | |
| dc.identifier.uri | http://dx.doi.org/10.26021/7568 | |
| dc.language.iso | en | |
| dc.publisher | University of Canterbury. Physics | en |
| dc.relation.isreferencedby | NZCU | en |
| dc.rights | Copyright Steven P. Jamison | en |
| dc.rights.uri | https://canterbury.libguides.com/rights/theses | en |
| dc.title | Laser site-selective spectroscopy of rare-earth ions in crystals of the fluorite structure | en |
| dc.type | Theses / Dissertations | |
| thesis.degree.discipline | Physics | en |
| thesis.degree.grantor | University of Canterbury | en |
| thesis.degree.level | Doctoral | en |
| thesis.degree.name | Doctor of Philosophy | en |
| uc.bibnumber | 688030 | |
| uc.college | Faculty of Science | en |
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