Restoration of the collinear spin arrangement in non-magnetic-ion-substituted M-type hexaferrite by high magnetic fields

Abstract We have succeeded in synthesizing BaAlxFe10−xTi2O19 samples from intermediate trivalent-iron compounds and Fe3O4. Applying high magnetic fields of μ 0 H ≃ 57 T to these samples caused their magnetization to approach the net magnetic moment of the ferrimagnetic arrangement of spins. This fact meant that the magnetic field restored the ferrimagnetic collinearity as in the starting material of the M-type hexaferrite (BaFe12O19) rather than inducing a spin-flip or spin-flop transition. This collinear spin arrangement model reasonably explains that the distribution of Ti cations in BaFe10Ti2O19 is similar to that in BaFe8Ti2Zn2O19 on the assumption that Fe2+ ions are at up-spin sites.