NEAR-INFRARED PHOTOLUMINESCENCE IN PHOSPHATE MINERALS AND RELATED GLASS-CERAMICS

Fertilizing glass-ceramics were prepared and characterized by photolum inescence (PL) spectroscopy. These materials, and some of the related phosphorites, unexpectedly exhibited intense PL emission in the near-i nfrared region. In the 1100-1250 nm range a very intense doublet at 11 61 and 1149 nm and a less intense band at 1274 nm were assigned to emi ssion from the uncommon ionic species Mn-V. Therefore, one of the d(2) ions such as Cr-IV and Mn-V which are of growing interest in the fiel d of solid-state lasers, was found in minerals for the first time. In order to obtain further information about these materials, structural and spectroscopic properties of the raw materials were recorded separa tely. As far as the coordination of Mn-V is concerned, the hypothesis of partial substitution of P-V by Mn-V in the phosphate lattice appear s to be quite reliable. Typical PL emission of neodymium was also obse rved both in glass-ceramics and in raw materials.