Chang, LiaoRoberts, AndrewMuxworthy, Adrian RTang, YanChen, QianwangRowan, Christopher JLiu, QuingsonPruner, Petr2015-12-070094-8276http://hdl.handle.net/1885/19232We report the magnetic properties of pure synthetic pseudo-single-domain (PSD) and multi-domain (MD) greigite and the grain size dependence of the magnetic properties of greigite for the first time. The dominantly PSD-like and MD-like behavior are demonstrated by hysteresis, first-order reversal curve diagrams, low-temperature cycling (LTC) of room temperature saturation isothermal remanent magnetization (SIRM) and low-temperature SIRM warming curves. Variations in a range of magnetic properties clearly correlate with grain size. Characteristic PSD/MD behavior is preserved at low temperatures, which, coupled with the small decrease in remanence during warming, rule out the presence of substantial superparamagnetic behavior in the studied samples. LTC-SIRM measurements indicate a continuous demagnetization of remanence during cooling. Knowledge of this expanded range of magnetic properties of greigite should be widely useful in environmental magnetic and paleomagnetic studies.Keywords: Curve fitting; Demagnetization; Grain size and shape; Magnetic hysteresis; Magnetic properties; Remanence; Saturation magnetization; Superparamagnetism; Thermal cycling; First-order reversal curve diagrams; Greigite; Low-temperature cycling (LTC); Saturat200710.1029/2007GL0321142015-12-07