Effect of intergrowths of the ferrimagnetic and antiferromagnetic phases on the rock magnetic properties of natural pyrrhotites
| Autor: | Karel Zapletal |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Materials science
Physics and Astronomy (miscellaneous) Condensed matter physics Magnetic domain Astronomy and Astrophysics engineering.material Magnetic hysteresis Magnetic susceptibility Magnetization Geophysics Space and Planetary Science Ferrimagnetism Remanence engineering Antiferromagnetism Pyrrhotite |
| Zdroj: | Physics of the Earth and Planetary Interiors. 76:151-162 |
| ISSN: | 0031-9201 |
| DOI: | 10.1016/0031-9201(93)90064-g |
| Popis: | Several types of massive natural pyrrhotites were characterized using low-field magnetic susceptibility and its anisotropy (AMS), thermomagnetic analysis and the colloid method. The pyrrhotites studied differed in the concentration of the ferrimagnetic (Fe7S8) phase (ranging from 100 to 5%), this phase being microscopically intergrown with the antiferromagnetic (Fe9S10) phase. An artificial specimen containing powdered pyrrhotite dispersed in a diamagnetic material was prepared from each pyrrhotite type; hysteresis curves of isothermal remanent magnetization (IRM) and AMS were measured on these specimens. The IRM induced in a 1 T field and the mean bulk susceptibility ( k ) of dispersed pyrrhotite specimens decrease with decreasing ferrimagnetic phase concentration in the pyrrhotites studied as follows: (1) the IRM (1 T) values range from 30.8 to 1.4 kA m−1; (2) the k values range from 217 × 10−3 to 7.1 × 10−3. During magnetization, AMS was induced in dispersed pyrrhotite specimens (which were nearly isotropic in their original state). |
| Databáze: | OpenAIRE |
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