Factors affecting the Nd super(3+) (REE super(3+)) luminescence of minerals

In this paper, possibilities and limits of the application of REE super(3+) luminescence (especially the Nd super(3+) super(4)F sub(3/2) arrow right super(4)I sub(9/2) emission) as structural probe are evaluated. Important factors controlling the Nd super(3+) 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 (ZrSiO sub(4)), xenotime-(Y) (YPO sub(4)), monazite-(Ce) (CePO sub(4)) and their synthetic analogues. Based on these examples we review in short that (1) REE super(3+) 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 REE super(3+)-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 Nd super(3+)-related centres are found to be promising candidates.