B. A. Sava, L. Boroica, M. Sava, M. Elisa, Vitreous potassium-phosphate materials containing nitrogen as agricultural fertilizers, Rev. Rom. Materials, 41/4 (2011) 371-382.

Title: Vitreous potassium-phosphate materials containing nitrogen as agricultural fertilizers

Abstract: The present work investigates vitreous fertilizers for agricultural purposes. The studied compositions belong to K(2)O - MgO - P(2)O(5) ternary system. The samples were investigated by IR and Raman spectroscopy, showing vibrations specific to P-O-P, PO(3)(2-), PO(2) and P = O bonds. In the case of AG.5 sample, IR peaks are shifted, indicating that nitrogen replaces oxygen in a great extent that modifies the vitreous phosphate network. XRD plots revealed specific shapes for glassy state both for un-nitrided and nitrided samples. SEM investigations on powders show more homogeneous darker phases in the case of AG 5 sample comparatively to AG 2 series.

Key words: phosphate glass; fertilizers; XRD; IR and Raman spectroscopy; SEM