Relation between the Hyperfine Magnetic Fields and Sublattice Magnetizations inFe3O4

Abstract

The temperature dependences of the hyperfine magnetic fields at ${\mathrm{Fe}}^{57}$ nuclei in $A$ and $B$ sites of ${\mathrm{Fe}}_3$ ${\mathrm{O}}_4$ have been determined with the Mössbauer-effect technique. A comparison with neutron diffraction data shows that the $H_{\mathrm{hpf}}$-versus-$T$ curves follow the sublattice-magnetization-versus-temperature curves very closely. Over the temperature range 300-800°K, the hyperfine constants for $A$ and $B$ sites in ${\mathrm{Fe}}_3$ ${\mathrm{O}}_4$ change less than 1%.