Christoph Lenz

Factors affecting the Nd3+ (REE3+) luminescence of minerals

In this paper, possibilities and limits of the application of REE3+ luminescence (especially the Nd3+4F3/2 → 4I9/2 emission) as structural probe are evaluated. Important factors controlling the Nd3+ luminescence signal are discussed, including effects of the crystal-field, crystal orientation, structural state, and temperature. Particular attention was paid to the study of the accessory minerals zircon (ZrSiO4), xenotime–(Y) (YPO4), monazite–(Ce) (CePO4) and their synthetic analogues. Based on these examples we review in short that (1) REE3+ luminescence can be used as non-destructive phase identification method, (2) the intensities of certain luminescence bands are strongly influenced by crystal orientation effects, and (3) increased widths of REE3+-related emission bands are a strong indicator for structural disorder. We discuss the potential of luminescence spectroscopy, complementary to Raman spectroscopy, for the quantitative estimation of chemical (and potentially also radiation-induced) disorder. For the latter, emissions of Nd3+-related centres are found to be promising candidates.

Luminescence database - an update

1 CSIRO Process Science and Engineering, Box 312, Clayton, VIC, 3169, Australia. 2 Laser Distance Spectrometry Ltd., Petah Tikva, Israel 3 Institut für Mineralogie, Technische Universität Bergakademie Freiberg, Germany 4 Institut für Mineralogie und Kristallographie, Universität Wien, Austria 5 Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, Canada 6 www.fluomin.org/uk/accueil.php Corresponding Author’s e-mail address: nick.wilson@csiro.au

A SXES and CL Spectral Library for the Analysis of Rare Earth Elements

Cathodoluminescence (CL) and soft x-ray emission (SXE) spectrometers are both sensitive to chemical bonding and offer insight into the local environment of rare earth ions. Rare earth (RE) containing minerals and materials often emit strong CL associated with the RE ion. The spectra are often complex and the relative peak intensities, position and width can all vary with both host composition and structure. Similarly SXE spectra of RE containing compounds show peak movement from changes in the host lattice and the structure. Since both can now be measured then they should both be used to offer extra insight into the RE environment. To investigate this we have collected a series of materials containing RE elements in different structures. These include the REE containing phosphates, fluorides manufactured by Charles M. Taylor, glasses made by University of Edinburgh, and various REE containing oxides and borides. The collected spectra will be added to the luminescence database [1] and made available through the website [2] and be included in the distribution set of spectra given out with OpticalFit [2].