Physical review. B, Solid state · 1975 · 104 citations · 16 references
The Mn₁₋ₓZnₓFe₂O₄ ferrite series (0 ≤ x ≤ 0.95) was examined by Mössbauer spectroscopy at 4.2 K under 50 and 90 kOe magnetic fields. All Mn₁₋ₓZnₓFe₂O₄ samples exhibit ferrimagnetism; as Zn increases, Fe occupancy on tetrahedral sites drops below 2 % at x = 0.6, B‑site Fe spins reverse for x ≥ 0.6, and magnetic moments shift from collinear (x < 0.5) to noncollinear (x > 0.5) with increasing canting angles that grow with Zn content and field, while the x = 0.80 composition shows the most stable structure and hyperfine parameters vary only slightly.
The disordered ferrite system, ${\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Zn}}_{x}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$ for $0\ensuremath{\le}x\ensuremath{\le}0.95$ has been studied by the M\"ossbauer-effect technique at 4.2 K in applied magnetic fields of 50 and 90 kOe. In these fields a ferrimagnetic structure is implied for the entire family of compounds. For $x=0$ the cation distribution is (${\mathrm{Mn}}_{0.82}$${\mathrm{Fe}}_{0.18}$)[${\mathrm{Mn}}_{0.18}$${\mathrm{Fe}}_{1.82}$]${\mathrm{O}}_{4}$; for larger $x$ the iron concentration on $A$ (tetrahedral) sites decreases, and becomes less than 2 at.% by $x=0.6$. For $x\ensuremath{\ge}0.6$, some of the Fe ions on $B$ (octahedral) sites have their spin moments reversed. Within the experimental error, the magnetic moments of the iron ions are collinear for $x<0.5$ and noncollinear for $x>0.5$. The canting angles for normal $B$-site cations are found to increase with increasing zinc content, and to depend on the applied field. The sample with $x=0.80$ has the most stable structure. The hyperfine fields and isomer shifts show only a small variation with sample composition.
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