Self-reversal of chemical remanent magnetization during multiphase oxidation of synthetic titanomagnetites

A. K. Gapeev, and S. K. Gribov

Borok Geophysical Observatory, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Borok, Yaroslavl oblast, Russia


[1]  The possibility of self-reversal of chemical remanent magnetization (CRM) is studied on synthetic samples of titanomagnetites (Fe3-xTixO4, where x = 0.2, 0.4, and 0.6) that experienced multiphase oxidation in air at 500oC in the presence of the constant magnetic field H = 0.1 mT. The self-reversal was fixed in accordance with anomalous behavior of CRM curves of cooling (in H = 0) and heating (in H = 0). Complete self-reversal of CRM is discovered experimentally in samples of oxidized titanomagnetites with initial x = 0.6, while partial self-reversal is revealed in other titanomagnetite compositions. Superposition of a partial thermoremanent magnetization (pTRM) on CRM showed that heating curves of CRM+pTRM are also anomalous, but negative values of the total magnetization are not observed.

Received 19 July 2008; accepted 22 August 2008; published 12 September 2008.

Keywords: titanomagnetite, oxidation, magnetization, self-reversal.

Index Terms: 1500 Geomagnetism and Paleomagnetism; 1518 Geomagnetism and Paleomagnetism: Magnetic fabrics and anisotropy; 1519 Geomagnetism and Paleomagnetism: Magnetic mineralogy and petrology; 1533 Geomagnetism and Paleomagnetism: Remagnetization; 1540 Geomagnetism and Paleomagnetism: Rock and mineral magnetism; 3630 Mineralogy and Petrology: Experimental mineralogy and petrology.


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