ISSN:
1432-2021
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Abstract The heat capacity of åkermanite solid solutions was measured by a small scale adiabatic calorimeter near the incommensurate-normal (I-N) transition. The heat capacity anomalies caused by the I-N transition show the λ type characteristic behavior implying the presence of dynamical fluctuations. The heat capacity anomalies were observed over the whole range of the åkermanite solid solutions Ca2Mg1-xCoxSi2O7 and Ca2Mg1-x-ZnxSi2O2. With increase of Co or Zn atoms, the transition temperature, Ti, rises linearly from ca. 83° C to 220° C and to 130° C, respectively. In the system Ca2CoSi2O7-Ca2FeSi2O7 and Ca2MgSi2O7-Ca2-FeSi2O7 electronic microscopy revealed that the temperature of the heat capacity anomaly decreases with increasing Fe content, whereas the Ti rises. This unusual behavior is ascribed to the microdomains observed in high resolution lattice images.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00202243
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