TRIPLE PHOSPHATES OF CALCIUM, SODIUM AND TRIVALENT ELEMENTS WITH WHITLOCKITE-LIKE STRUCTURE

Triple phosphates of calcium, sodium and trivalent elements (Eu, Nd, F e) in Ca-3(PO4)(2)-RPO(4)-Na3PO4 systems were predicted on the basis o f crystal chemistry data and synthesized. The obtained phases were stu died by XRD, IR-spectroscopy and emission spectroscopy under Sr-90-Y-9 0 and lambda = 380 nm excitation. The only phosphates with the whitloc kite-like structure appear within the range of (PO4)(2)-Ca(9)Na(1.5)R( 0.5)(PO4)(7)-Ca10Na(PO4)(7) composition. The emission spectra of phase s with europium under Sr-90-Y-90 excitation consist of transition line s D-5(0)--> F-7(j) in EU(3+) and two broad bands of inherent luminesce nce of the matrix with maximums at similar to 360 and similar to 510 n m.