Transition path selection between ammonium nitrate solid phases IV, III and II
Abstract
Study was made of factors affecting the transition paths between ammonium nitrate solid state phases IV, III and II. The effect of the sample preparation method was investigated by differential scanning calorimetry (DSC), transition mechanisms were explored with simultaneous DSC and Raman spectrometry developed for in situ investigation of the transitions, and the relationship between phase IV structure and the transition paths was studied by X-ray powder diffraction (XRD) and DSC. The results were analysed by partial least-squares regression (PLS) and principal component analysis (PCA). Three categories of transitions were observed: a) the principal transitions IV ↔ III ↔ II and IV ↔ II, b) the parallel transitions IV → III → II and IV → II on heating or II → III → IV and II → IV on cooling and c) the forward-and-back transitions IV → II (→ III → II) on heating and II → IV (→ III → IV) on cooling. The phase transition paths were shown to be influenced by the sample preparation method, which evidently affects the degree of disorder of phase IV. The existence of an intermediate phase II* between phases IV and III was confirmed. The life-time of II* was seven minutes maximum and decreased with decreasing transition temperature. The multivariate analysis of XRD and DSC data showed that a relationship exists between the XRD patterns and the transition paths and confirmed that PLS could be used to predict the transition path that the sample would undergo on heating. PCA indicated seven per cent of the variation in the XRD patterns to be related to the structural factors connected with the phase transition path selection.
Main Author
Format
Theses
Doctoral thesis
Published
1994
Series
Annales Academiae scientiarum Fennicae. Series A 2, Chemica
Suomalaisen tiedeakatemian toimituksia. Sarja A 2, Chemica ;
Suomalaisen tiedeakatemian toimituksia. Sarja A 2, Chemica ;
Subjects
ISBN
951-41-0737-3
Publisher
Suomalainen tiedeakatemia
Original source
http://www.acadsci.fi/julkaisut/chemica253_harju.pdf
The permanent address of the publication
https://urn.fi/URN:ISBN:951-41-0737-3Use this for linking
ISSN
0066-1961
Description
Article dissertation. Contains an introduction and five articles.
Language
English
Published in
Annales Academiae scientiarum Fennicae. Series A 2, Chemica
Suomalaisen tiedeakatemian toimituksia. Sarja A 2, Chemica ;
Contains publications
- Artikkeli I: Harju, M. E. E. and Valkonen, J. (1993). Effect of sample treatment on the phase transition paths of ammonium nitrate solid state phases IV, III and II. J. Thenn. Anal. 39, 681.
- Artikkeli II: Harju, M. E. E., Valkonen, J. and Jayasooriya, U. A. (1991). Simultaneous application of Fourier transform Raman spectrosroscopy and differential scanning calorimetry for the in situ investigation of phase transitions in condensed matter. Spectrochim. Acta, Part A: 47, (1991) 1395. Erratum, Spectrochim. Acta, Part A: 49, (1993). DOI: 10.1016/0584-8539(91)80230-G
- Artikkeli III: Harju, M. E. E., Valkonen, J., Jayasooriya, U. A., Wolverson, D. (1992). Simultaneous application of charge coupled device array-detected Raman spectroscopy and differential scanning calorimetry to in situ investigation of phase transitions in condensed matter. J. Chem. Soc., Faraday Trans., 88, 2717. DOI: 10.1039/FT9928802717
- Artikkeli IV: Harju, M. E. E. (1993). Solid-state transition mechanisms of ammonium nitrate phases IV, III and II investigated by simultaneous Raman spectrometry and differential scanning calorimetry. Appl. Spectrosc. 47, 1926. DOI: 10.1366/0003702934066127
- Artikkeli V: Harju, M. E. E., Minkkinen, P. and Valkonen, J. (1994). Transition paths between phases IV, III and II of ammonium nitrate predicted from Xray powder diffractometer and differential scanning calorimeter data by partial least-squares regression. Chemometrics and Intelligent Laboratory Systems, 23(2), 341-350. DOI: 10.1016/0169-7439(93)E0085-I
Citation
- Harju, Mauno E. E. (1994). Transition path selection between ammonium nitrate solid phases IV, III and II, Finland: Suomalainen tiedeakatemia. Annales Academiae scientiarum Fennicae, ISSN 0066-1961; 253. Retrieved from http://www.acadsci.fi/julkaisut/chemica253_harju.pdf
License
Copyright© 1994 by Academia Scientiarum Fennica