Low-temperature remanence in stable single domain magnetite

A numerical model is developed in order to simulate the loss of low-temperature remanence while warming through the Verwey transition. We concentrate on the amount of remanence lost (δ_fc and during field cooled and zero field cooled low temperature demagnetization curves for stable single domain (SSD) particles of (1) inorganic magnetic and (2) biogenic magnetite in the form of magnetosome chains. The model predicts that delta ratios (δ_fc/δ_zfc) for inorganic SSD magnetite increase from 1 to 1.6 with increasing aspect ratio and that magnetosome chains have elevated delta ratios of at least 2.0. Disaggregated magnetosomes are predicted to behave similarly to inorganic acicular SSD magnetite. The numerical results agree with experimental results.