Abstract
29Si MAS NMR spectra of synthetic akermanite, Ca2MgSi2O7, exhibit a splitting into three or more lines in the stability feld of the low-temperature incommensurate phase. With increasing temperature, these lines continuously merge into a single line which is then characteristic of the high-temperature, melilite-type structure. The data point to the non-equivalence of Si sites in the low-temperature phase and the gradual structural changes as the phase transition temperature is approached.
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Merwin, L.H., Sebald, A. & Seifert, F. The incommensurate-commensurate phase transition in akermanite, Ca2MgSi2O7, observed by in-situ 29Si MAS NMR spectroscopy. Phys Chem Minerals 16, 752–756 (1989). https://doi.org/10.1007/BF00209697
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DOI: https://doi.org/10.1007/BF00209697