Structural, characterization and spectroscopic properties of NH4YbP2O7 micro-powders

Powders of NH4YbP2O7 diphosphate have been grown using the flux method. This compound was found to be isotopic to RbYP2O7. It crystallizes in the monoclinic space group P21/c with unit cell parameters: a = 7.7038(6) Å; b = 19.924(7) Å; c = 8.625(2) Å and β = 105.239(5)°. Thermal treatment of NH4YbP2O7 up to 550 °C allowed us to obtain Yb(PO3)3 triphosphate. Powder X-ray diffraction, vibrational spectroscopy and particle-size distribution have been used to identify these materials. Spectroscopic properties of the Yb3+ in both compounds NH4YbP2O7 and Yb(PO3)3, at room temperature (RT) have been carried out. Absorption spectra of Yb3+ ion in both phosphates have been registered. A broad band located between 970 nm and 1060 nm relative to the Stark levels of the Yb 4f configuration is observed. The excitation and emission spectra in UV–vis and IR range have been registered. Calcinations effect on the PL measurements, have been observed. They show that the position of the charge transfer band (CTB) depends on the host lattices.