Reversed exchange-bias effect associated with magnetization reversal in the weak ferrimagnet LuFe0.5Cr0.5O3

Abstract

The exchange-bias (EB) effect with sign reversal was found in LuFe 0.5 Cr 0.5 O 3 ferrite-chromite, which is a weak ferrimagnet below T N = 265 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 comp = 230 K, leading to the net magnetic moment reversal and to observed negative magnetization, at moderate applied fields, below T 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 comp and negative above T comp , with nonmonotonic dependence on cooling field H cool. It sharply increases at small values of magnetic fields up to H cool ∼ 1 kOe, then remains almost unchanged in the range 1-30 kOe and strongly decreases with further increase of H cool. This unusual behavior results from the competition of various Dzyaloshinskii-Moriya interactions between Fe 3+ and Cr 3+ ions.

Dzyaloshinskii Interaction and Exchange-Relativistic Effects in Orthoferrites

“…Weak ferrimagnets can exhibit the tunable exchange bias (EB) effect [83]. Recently the EB effect with reversal sign was found in LuFe 0.5 Cr 0.5 O 3 ferritechromite [84] which is a weak ferrimagnet below T N = 265 K, exhibiting antiparallel orientation of the mean weak ferromagnetic 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 comp = 230 K, leading to the net magnetic moment reversal and to observed negative magnetization, at moderate applied field, below T comp .…”

Dzyaloshinskii–Moriya Coupling in 3d Insulators

“…The compound also displays both normal and inverse magnetocaloric effects above and below 260 K, respectively. Recently the exchange bias (EB) effect was studied in LuFe 0.5 Cr 0.5 O 3 ferritechromite [71,72] which is a weak ferrimagnet below T N = 265 K, exhibiting antiparallel orientation of the mean weak ferromagnetic moments (FM) of the Fe and Cr sublattices due to opposite sign of the Fe-Cr Dzyaloshinskii vector as compared with that of Fe-Fe and Cr-Cr. Weak ferrimagnets can exhibit the tunable exchange bias effect [73] and have potential applications in electromagnetic devices [70].…”

Unveiling ferrimagnetic ground state, anomalous behavior of the exchange-bias field around spin reorientation, and magnetoelectric coupling in YbCr1−xFexDalal1, Sarkar2, Rayaprol3 et al. 2020Phys. Rev. B19140View full textAdd to dashboardCite

“…Thus, the complex dielectric behavior along with the temperature induced MR phenomenon in both ZFC and FC mode, and ZFC exchange bias effect [27] makes using this particular material (YbCrO 3 ) fascinating to carry out the fundamental research. Moreover, the emergence of various extraordinary phenomena, such as, spin reorientation, metamagnetic transition, multiferroicity, and reversed exchange bias effect, in the complete solid-solution between rare-earth orthochromites, orthoferrites, and cobaltites [32][33][34][35][36][37][38][39][40][41][42][43][44][45] stimulated us to revisit the solid-solution of rare-earth orthochromites and orthoferrites, and explore some intriguing physical characteristics in more detail. In this context, we choose to investigate YbCr 1−x Fe x O 3 , as the parent compound YbCrO 3 exhibits many interesting magnetic properties; whereas, Fe doping might provide the suitable platform to induce complex magnetic ordering, and type-II multiferroicity (and/or, magnetoelectric coupling) through local charge ordering and/or, magnetic frustration [46].…”