Title :
The Role of Atmosphere on Phase Transformations and Magnetic Properties of Ulvospinel
Author :
Groschner, Catherine ; Song Lan ; Wise, Andrew ; Leary, Alex ; Lucas, Matthew S. ; Changyong Park ; Laughlin, David E. ; Diaz-Michelena, Marina ; McHenry, Michael E.
Author_Institution :
Mater. Sci. & Eng. Dept., Carnegie Mellon Univ., Pittsburgh, PA, USA
Abstract :
We have synthesized the antiferromagnetic mineral ulvospinel, Fe2TiO4, in Ar to assess the role of inert atmosphere on phase formation and magnetic properties. We report the role of atmosphere on a possible phase transition and the magnetic properties of this mineral. Atmosphere dependent transformations of ulvospinel are observed with increasing temperature. Oxidation of ulvospinel to form metastable titanomaghemite is shown to occur at 300° in atmospheric conditions. Only slight titanomaghematitzation was observed in samples transformed under pressure in in situ temperature dependent X-ray experiments. Formation of ilmenite and hematite from ulvospinel was observed under high temperature, high pressure, and low oxygen atmosphere conditions.
Keywords :
Neel temperature; X-ray diffraction; antiferromagnetic materials; high-pressure solid-state phase transformations; high-temperature effects; iron compounds; magnetisation; minerals; oxidation; Fe2TiO4; Neel temperature; X-ray diffraction; antiferromagnetic mineral ulvospinel; atmosphere dependent transformation; hematite formation; high-pressure effects; high-temperature effects; ilmenite formation; in situ temperature; low oxygen atmosphere condition; magnetic properties; magnetization; metastable titanomaghemite formation; oxidation; phase transformations; temperature 300 degC; titanomaghematitzation; Atmosphere; Magnetic properties; Magnetization; Magnetosphere; Minerals; Temperature; X-ray scattering; Martian mineral; remnant magnetization; thermal magnetic property; titanomagnetite;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2013.2250928
