Magnetic and Photon Cascade Emission of Gd3+ of NaGd(PO3)4 Monocrystal Under Appropriate Synthesis Conditions

Abstract

A signal crystal of NaGd(PO3)4 (NGP) was successfully grown with the solid-state reaction method under appropriate synthesis conditions. Structure refinements and the purity of the samples were determined by XRD patterns. It reveals that NaGd(PO3)4 compound crystallizes in the monoclinic system with P 21/n space group and with cell parameters a=7.174(1) A, b=13.033(2) A, c=9.781(1) A, β=90.65(2)°, V=914.47(20) A3 and Z=4. The IR and Raman spectra also indicated that the phosphoric polyhedra of NaGd(PO3)4 has a acyclic symmetry. Differential thermal analysis is given. This compound is thermally stable until 852°C. The magnetic susceptibilities of gadolinium polyphosphate as a function of temperature are reported along with corresponding magnetization measurements. This polyphosphate displays a paramagnetic response, without magnetic phase transitions, and with effective magnetic moments close to those of the corresponding free Gd3+ ions. The luminescence proprieties of Gd3+ was investigated. The emission spectra NGP exhibit intense band at 315 nm due to 6P7/2 →8S7/2 transition of Gd3+ ions when excited at 273 nm. The photon cascade emission (PCE) of Gd3+ has been proved at 164 and 254 nm excitation.