It is known that magnetite transforms from cubic to monoclinic structure at a transition temperature (Verwey transition, Tv), where magnetic anisotropy and resistivity change abruptly . In the temperature Vs coercivity plot this effect is noticeable, where a isotropy point (near to Tv) is observed, showing the minimum coercivity (even less than the room temperature value).  I have also observed this kind of coercivity lowering at 125 K for maghemite nanoparticles of around size 5 nm, while my sample has not shown any Verwey transition at M-T measurement and also ideally it should not show.  

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