%0 Journal Article
%A Almeida, Trevor P.
%A Muxworthy, Adrian R.
%A Williams, Wyn
%A Kasama, Takeshi
%A Dunin-Borkowski, Rafal
%T Magnetic characterization of synthetic titanomagnetites: Quantifying the recording fidelity of ideal synthetic analogs
%J Geochemistry, geophysics, geosystems
%V 15
%N 1
%@ 1525-2027
%C Hoboken, NJ
%I Wiley
%M FZJ-2015-02609
%P 161 - 175
%D 2014
%X A series of four synthetic basalts comprising titanomagnetite (Fe3-xTixO4) grains of varied size and titanium content have been produced by a glass-ceramic method. Complementary characterization techniques of X-ray diffractometry, secondary electron microscopy, and transmission electron microscopy (TEM) demonstrate the reaction product composition consisted of mainly Fe3-xTixO4, pyroxene hedenbergite, fayalite, and SiO2. The samples exhibit bimodal distributions of larger (<2 µm) and smaller Fe3-xTixO4 particles (<50 nm in diameter), the latter found inside pyroxene crystals, as well as the sporadic occurance of dendritic Fe3-xTixO4 structures. Magnetic measurements show their bulk characteristics fall into two groups: Ti-rich titanomagnetite samples with varying Ti content; and near-stoichiometric magnetite. The TEM technique of off-axis electron holography allowed for visualization of the magnetic behavior of the synthetic Fe3-xTixO4 grains. Energy dispersive X-ray analysis and off-axis electron holography confirmed the small Fe3-xTixO4 grains (<50 nm) confined within glassy pyroxene regions to be Fe-rich and single domain, carrying strong magnetic signals, compared to the relatively magnetically weak larger Fe3-xTixO4 grains (x ∼ 0.6). The large grains in the pure magnetite sample are shown to be pseudo-single domain in nature. The quenching process involved in synthesis is considered similar to that of pillow basalts found at mid-ocean ridges and hence the reaction products are thought ideal in terms of characterization and understanding, for the purpose of studying natural systems.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000331441500010
%R 10.1002/2013GC005047
%U https://juser.fz-juelich.de/record/189442