Walters, Robin V. (1989) Investigation of the phase transitions in the alkali metal nitrites using Raman spectroscopy. Masters thesis, Memorial University of Newfoundland.
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The alkali metal nitrites have been studied from 77 K through the phase transitions and in the molten state by Raman spectroscopy. With the exception of LiNO₂, all the alkali metal nitrites go through at least one solid-solid phase transition. The presence of NO₂ groups disordered over non-equivalent crystallographic sites is a common feature of at least one phase for each salt. -- The results for LiNO₂ are not consistent with the suggested D⁵₃d crystal structure. Spectroscopic evidence and ab initio calculations indicated that the NaNO₂ order-disorder transition occurs via a nitrite rotation about the crystallographic a axis. No evidence was obtained for the reported phase transitions at 343 or 380 K in KNO₂ or for the high temperature phase transition in CsNO₂. For RbNO₂, the effect of nitrate impurity was considered. The spectroscopic observables are discussed in relation to available thermodynamic quantities.
|Item Type:||Thesis (Masters)|
|Additional Information:||Bibliography: leaves 163-167.|
|Department(s):||Science, Faculty of > Chemistry|
|Library of Congress Subject Heading:||Nitrites--Spectra|
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