Successive Phase Transitions in Nearly Stoichiometric ErFe₂O₄

Charge-Stripe Order in the Electronic FerroelectricLuFe2O4

“…Our TEM observations reveal a variety of interesting microstructure features from room temperature down to 20 K. diffuse streaks on (h/3, h/3, l) lines along c*-direction. Moreover, the superstructure reflections always contain notable contributions from the CO twinning, which often results in a zig-zag type of superstructure streaks as noted in previous publications 1,15 . The average thickness of the CO lamellae at room temperature is estimated to be smaller than 5 nm.…”

Interplay betweenR4fand Fe3dstates in charge-orderedKim1, Hwang2, Lee3 et al. 2013Phys. Rev. B12180View full textAdd to dashboardCite

“…The FC curve of R = Er exhibits two anomalies at T C1 ≈ 240 and T C2 ≈ 210 K. The second transition at T C2 arose from the structural transition to monoclinic phase. 22 In R = Er, the ZFC magnetization is extraordinarily higher than the FC magnetization near T C ≈ 240 K. 31 This feature is expected to come from the hysteresis behavior accompanied by the structural transition, or reflects the very large magnetic anisotropy near T C . The FC curve of R = Lu shows a slight decrease below T ≈ 170 K, which is also related to the structural distortion subsequent to the magnetic ordering.…”

“…All three samples show the ferrimagnetic transition at T C ≈ 240 K, in agreement with those in other RFe 2 O 4 . 22,28,29 For R = Tm and Lu, the larger magnetization is observed under field cooling, which is characteristic of a cluster glass system 30 and considered to originate from the growing size of the magnetic domains along H . The cluster glass behavior in RFe 2 O 4 is expected because of its generic nature of the geometrical and magnetic frustration.…”

Ferroelectricity from iron valence ordering in rare earth ferrites?

“…Single-crystal neutron diffraction confirmed a tendency towards 3D long-range order for samples closer to stoichiometry [30], but due to the absence of sufficiently stoichiometric crystals until recently [31], the magnetic structures remain unsolved. Such a sample-dependence was observed also for Er [32] and Lu (see Fig. 3), although the link to O-stoichiometry [33] is less clear, mostly due to the range of stoichiometries for which long-range order is observable shrinking with decreasing R 3+ size (c.f.…”