Regensburg 2013 – wissenschaftliches Programm
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KR: Fachgruppe Kristallographie
KR 2: Multiferroics 2 (MA jointly with DF, DS, KR, TT)
KR 2.5: Vortrag
Montag, 11. März 2013, 16:00–16:15, H3
Ab initio study of magneto-phonon interaction in GaFeO3 — •Konstantin Z. Rushchanskii, Stefan Blügel, and Marjana Ležaić — Peter Grünberg Institut, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
Magnetoelectric (ME) coupling provides a handle for manipulating the magnetization of a material with an electric field, giving a perspective for a new type of non-volatile memory. Unfortunately, materials with ME coupling that is large enough for industrial applications are scarce. Moreover, among the materials which are both ferroelectric and magnetic at room temperature, only BiFeO3 is known. Unfortunately, the ordering of spins in this material is antiferromagnetic (whereas ferro/ferrimagnetic coupling is desired) and the ME coupling is small.
GaFeO3 (GFO) is the first material observed to simultaneously present a strong ME coupling and a resulting magnetization in a single phase. It has the polar structure Pc21n, which allows disorder in A and B cation sites. By increasing the iron content its Curie temperature can be increased above room temperature [1].
To understand the mechanism of the strong ME coupling in GaFeO3 at the microscopic level, we performed ab initio calculations based on density functional theory of the structural properties and magneto-phonon interaction in stoichiometric GaFeO3 compounds in different structures, as well as with different occupancies of the A and B sites.
We acknowledge the support by Helmholtz Young Investigators Group Programme VH-NG-409 and GALIMEO Consortium.
[1] T. Arima et al., Phys. Rev. B 70, 064426 (2006)