Structural Investigation of Oxy-thio Phosphate glasses and their Physical Properties

The short-range order (SRO) structures of the Na4P2S (7-x) O(x), 0 ≤ x ≤ 7, glass system was investigated, using samples that were prepared with the ball milling technique. This glass series was explored using X-Ray diffraction (XRD), Raman, Fourier Transform infrared (FT-IR), and 31P Magic Angle Sample Spinning NMR (MAS NMR) spectroscopies to develop an understanding of how incorporating oxygen into the sulfide structure affects the physical properties. XRD was used to show that the ball milled samples can be prepared as completely amorphous materials, and the spectroscopy experiments combine to show that the materials are completely chemically reacted in the samples. The structual transformation caused by the incremental addition of oxygen can by seen in the progression from pyro-phosphate (P1) units to ortho-phosphate (P0) and meta-phosphate (P2) units. These structural changes can also be seen in the trends of the physical properties as the glass transition temperature increases and the ionic conductivity decreases