Anomalous temperature dependence of the first diffraction peak in the superionic glass(AgI)x(AgPO3)1−x

• DOI: 10.1103/physrevb.61.1036
• Publication Date: 2002-07-27T02:02:38Z
• Authors: E. Kartini; M. F. Collins; T. Priyanto; M. Yusuf; N. Indayaningsih; E. C. Svensson; S. J. Kennedy
• Keywords: 0103 physical sciences; 01 natural sciences

We report neutron-scattering measurements on the first sharp diffraction peak in the superionic conducting glass $(\mathrm{AgI}{)}_{x}({\mathrm{AgPO}}_{3}{)}_{1\ensuremath{-}x}$ as a function of composition x from 0.0 to 0.7. The temperature variation is studied in detail between 300 K and 500 K, a range that spans the calorimetric glass transition. This peak reflects structure in the phosphate network with periodicity $d\ensuremath{\approx}10\AA{}$ and correlation length $\ensuremath{\approx}25\AA{}.$ The intensity of the first sharp diffraction peak shows an anomaly as a function of temperature at a temperature about 6--11 % higher than ${T}_{g}$ as measured calorimetrically. This is tentatively ascribed to the diffraction intensity reflecting the onset of $\ensuremath{\alpha}$ relaxation, while the calorimetric data reflects the onset of $\ensuremath{\beta}$ relaxation.