STABILIZATION OF DIVALENT NEODYMIUM (ND2+) IN STRONTIUM TETRABORATE

Luminescence and absorption spectra from SrB4O7:Nd2+ samples prepared from Nd2O3 (1 mol% based on Sr2+ ion mass) in air at high temperatures have been recorded at room temperature. A broad emission band centere d in the vicinity of 560 nm has been observed from the samples upon ex citation at 514.5 nm. We suggest that it is due to emission from the 5 d band in Nd2+ ion into its ground state 4f level (I-5(4)). Analysis o f absorption spectra recorded from the same samples support this concl usion. SrB4O7:Nd2+ samples prepared in Ar/H-2(4%) atmosphere exhibited more strongly the optical characteristics of Nd2+ ion compared to sam ples prepared in air. Several conditions promoting the stabilization o f Nd2+ ion in this matrix are discussed. The range of f-element reduci bility and stabilization in SrB4O7 has been extended from Tm2+ to Nd2 in the present work; however, the limit of this facile reduction proc ess has not yet been determined.