Creator |
|
|
|
Language |
|
Publisher |
|
|
Date |
|
Source Title |
|
Vol |
|
Issue |
|
First Page |
|
Last Page |
|
Publication Type |
|
Access Rights |
|
JaLC DOI |
|
Abstract |
The phase relationships in the jacobsite (MnFe_2O_4)-galaxite(MnAI_2O_4) join have been investigated by means of the conventional hydrothermal technique. The spinel phases were synthesized using two k...inds of starting materials: oxalate mixtures and nitrate gels. The crystallization processes were also examined at 2kb and 700°C. A solvus curve between jacobsite and galaxite was determined under various oxygen fugacities at total pressure 2kb and temperature below 750°C. The unmixing area enlarges with increasing oxygen fugacity, especially at the galaxite composition side. The solubility of iron and manganese ions in galaxite may be a good indicator of oxygen fugacity. The products were determined chemically with an electron probe microanalyzer. The compositions of synthesized spinel deviate from the ideal MnFe_2O_4- MnAI_2O_4 join, which is shown to be pseudobinary. The cell dimension of the synthetic jacobsite is corresponding with those of the synthesized and natural specimens within experimental error. The cell dimension of synthetic galaxite becomes smaller with decreasing oxygen fugacity.show more
|