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

Volume

49

Issue

7

fYear

2013

fDate

Jul-13

Firstpage

4273

Lastpage

4276

Abstract

We have synthesized the antiferromagnetic mineral ulvospinel, Fe₂TiO_4, 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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2013.2250928

Filename

6559128