RAMAN FREQUENCIES CALCULATED FROM THE VOLUME DATA AS A FUNCTION OF TEMPERATURE AT HIGH PRESSURES FOR THE DISORDERED PHASE II OF NH4I

---

Copy For Citation

YURTSEVEN H. H., Kavruk D.

INTERNATIONAL JOURNAL OF MODERN PHYSICS B, vol.25, no.4, pp.511-519, 2011 (SCI-Expanded)

• Publication Type: Article / Article
• Volume: 25 Issue: 4
• Publication Date: 2011
• Doi Number: 10.1142/s0217979211058146
• Journal Name: INTERNATIONAL JOURNAL OF MODERN PHYSICS B
• Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
• Page Numbers: pp.511-519
• Middle East Technical University Affiliated: Yes

Abstract

In this study, we calculate the Raman frequencies as a function of temperature for the fixed pressures of 706, 1080 and 6355 bars using the volume data for phase 11 of ammonium iodide. The Raman frequencies calculated here are for the translational optic nu(5) TOM (125 cm(-1)) lattice mode that is located at the zone boundary (M point) of the Brillouin zone of phase II for NH4I. For this calculation the volume data obtained at zero pressure, is used through the mode Gruneisen parameter for the disordered phase II (13 phase) which has the CsCI structure of NH4I.