Magnetic characteristics of synthetic pseudo‐single‐domain and multi‐domain greigite (Fe3S4)

Abstract

We 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.