Magnetic fatigue of magnetite: effect of cyclic loading under elevated temperatures on the magnetic and microstructural behavior
Dr. Boris Reznik
Prof. Dr. Agnes Kontny
Prof. Dr. Frank Schilling (Institute of Applied Geosciences - Division of Petrophysics, KIT)
Dr. Mario Walter (Institute of Applied Materials, KIT)
Magnetic properties of rocks are influenced by deformation processes within the Earth’s crust, ranging from slow processes in plate tectonics, through volcanic eruptions to the high-dynamic meteoritic impacts. Up to now, modifications of magnetic properties are mainly investigated in relation to static deformation. However, it is generally accepted that tectonic stresses first accumulate non-uniformly, and then rapidly increase. Such a rapid stress increase may be especially dominant if the tectonic loading exhibits a cyclic or a fatigue character at elevated temperatures. This assumption raises the question whether magnetic properties of rocks are sensitive to cyclic deformation at elevated temperatures. For this purpose, samples prepared from an iron ore, granite and single crystals of magnetite will be cyclically loaded under various conditions and subsequently studied by different magnetic and microstructural methods.