Dresden 2017 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 9: Poster Session
DF 9.31: Poster
Dienstag, 21. März 2017, 14:00–16:00, P1C
Tuning spin and charge orders in geometrically frustrated rare earth ferrites — •Sabreen Hammouda, Thomas Müller, Jörg Perßon, and Manuel Angst — JCNS-2, Forschungszentrum ,Jülich, Germany
Rare earth ferrites RFe2O4 have attracted a lot of attention as prototypical examples of multiferroics, which have a potential use in information technology in particular due to their proposed new mechanism of ferroelectricity arising from charge ordering (CO) of Fe2+ and Fe3+ in the Fe/O bilayers [1]. The YbFe2O4 exhibits a behavior very similar to LuFe2O4 [2], consistent with the primary importance of the rare earth ion size, which is comparable for both Yb3+ and Lu3+. Alternatively, the Y3+ ionic radius is much larger, and a completely different charge order was found [3].
Given the completely different CO in LuFe2O4, and YFe2O4, it is of high interest to study ”how charge and spin orders change while tuning the relevant interactions by gradually increasing the rare earth ion radius, made by substitution”, i.e. the substitution LuxY1−xFe2O4. However, a critical aspect have to be considered in such a study is that, for each substitution level x, the oxygen-stoichiometry needs to be fine-tuned, as otherwise O-stoichiometry changes are impossible to cleanly disentangle from the rare earth substitution.
I will present results from substituting Y (larger ion size) by the smaller Lu i.e. LuxY1−xFe2O4, particularly for x=0.5.
[1] Ikeda et al., Nature 436, 1136 (2005). [2] Williamson et al., unpublished. [3] T. Mueller et al., J. Crystal Growth 428, 40 (2015).