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Reversed exchange-bias effect associated with magnetization reversal in the weak ferrimagnet LuF e 0.5 C r 0.5 O 3 </mml:msub…

2018; American Physical Society; Volume: 97; Issue: 10 Linguagem: Inglês

10.1103/physrevb.97.104416

2469-9977

I. Fita, V. Markovich, A. S. Moskvin, A. Wiśniewski, R. Puźniak, P. Iwanowski, C. Martin, A. Maignan, Raúl E. Carbonio, M. Gutowska, A. Szewczyk, G. Gorodetsky,

Magnetic Properties and Synthesis of Ferrites

The exchange-bias (EB) effect with sign reversal was found in $\mathrm{LuF}{\mathrm{e}}_{0.5}\mathrm{C}{\mathrm{r}}_{0.5}{\mathrm{O}}_{3}$ ferrite-chromite, which is a weak ferrimagnet below ${T}_{\mathrm{N}}=265\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, exhibiting antiparallel orientation of the ferromagnetic (FM) moments of the Fe and Cr sublattices due to opposite sign of the Fe-Cr Dzyaloshinskii vector, as compared to that of the Fe-Fe and Cr-Cr. The weak FM moments of the studied compound compensate each other at temperature ${T}_{\mathrm{comp}}=230\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, leading to the net magnetic moment reversal and to observed negative magnetization, at moderate applied fields, below ${T}_{\mathrm{comp}}$. Both vertical and horizontal shifts from the origin were gotten in the field-cooled magnetization hysteresis loops. The EB sign was found to be positive below ${T}_{\mathrm{comp}}$ and negative above ${T}_{\mathrm{comp}}$, with nonmonotonic dependence on cooling field ${H}_{\mathrm{cool}}$. It sharply increases at small values of magnetic fields up to ${H}_{\mathrm{cool}}\ensuremath{\sim}1\phantom{\rule{0.16em}{0ex}}\mathrm{kOe}$, then remains almost unchanged in the range 1--30 kOe and strongly decreases with further increase of ${H}_{\mathrm{cool}}$. This unusual behavior results from the competition of various Dzyaloshinskii-Moriya interactions between $\mathrm{F}{\mathrm{e}}^{3+}$ and $\mathrm{C}{\mathrm{r}}^{3+}$ ions.