Chemical preparation and thermal behaviour of neodymium cyclotriphosphate tetrahydrate NdP_3O_9 centre dot 4H_2O

摘要

A new neodymium cyclotriphosphate tetrahydrate NdP_3O_9 centre dot 4H_2O has been prepared using a classical method of aqueous chemistry and characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG) and infrared spectroscopy which shows the characteristic bands of cyclotriphosphates as the triplet in the 1340-1260 cm~(-1) area. The results of differential thermal analysis, X-ray powder diffraction and IR spectrum of the compound heated at different temperatures showed that, after dehydration, NdP_3O_9 centre dot 4H_2O decomposes into an amorphous compound with a dehydration energy equals to 0.162 kJ g~(-1), then it crystallises at 925 K in order to give the polyphosphate Nd(PO_3)_3.