Triple phosphates of calcium, sodium and trivalent elements with whitlockite-like structure

Triple phosphates of calcium, sodium and trivalent elements (Eu, Nd, Fe) in Ca3(PO4)2-RPO4-Na3PO4 systems were predicted on the basis of crystal chemistry data and synthesized. The obtained phases were studied by XRD, IR-spectroscopy and emission spectroscopy under 90Sr-90Y and λ = 380 nm excitation. The only phosphates with the whitlockite-like structure appear within the range of Ca3(PO4)2-Ca9Na1.5R0.5(PO4)7-Ca10Na(PO4)7 compositi The emission spectra of phases with europium under 90Sr-90Y excitation consist of transition lines 5D0 → 7Fj in Eu3+ and two broad bands of inherent luminescence of the matrix with maximums at ~ 360 and ~ 510 nm.