Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 24: Magnetic Semiconductors
MA 24.8: Vortrag
Mittwoch, 25. März 2009, 16:30–16:45, HSZ 401
Magnetization Control in Multifunctional Heterostructures — •M. Althammer1, C. Bihler2, W. Schoch3, W. Limmer3, R. Gross1, M. S. Brandt2, and S. T. B. Goennenwein1 — 1Walther-Meißner-Institut, Garching, Germany — 2Walter Schottky Institut, Garching, Germany — 3Institut für Halbleiterphysik, Ulm, Germany
The functionality of magnetoelectronic devices depends on the efficiency and scalabilty of magnetization control schemes. We here discuss the voltage control of magnetization orientation via the magnetoelastic channel in ferromagnetic semiconductor/piezoelectric actuator hybrid structures. The hybrids consist of a thin Ga0.955Mn0.045As film cemented onto a piezoelectric actuator [1]. Using anisotropic magnetoresistance techniques, we have quantitatively determined the magnetic anisotropy within the plane of the Ga0.955Mn0.045As films. Exploiting the substantial changes of the magnetic anisotropy in Ga0.955Mn0.045As as a function of temperature T, different ratios between the magnetoelastic and the magnetocrystalline anisotropies can be realized in one and the same sample. At T=5 K the magnetoelastic anisotropy term is only a small contribution to the total anisotropy, so that only the coercive fields are slightly modified as a function of the control voltage. For T=50 K the magnetoelastic contribution dominates the magnetic anisotropy which allows to achieve a voltage control of the magnetization orientation by about 70∘.
Financial Support by the DFG (SPP 1157, Li 988/4 and GO 944/3) is gratefully acknowledged.
[1] Bihler, et al., PRB 78, 045203 (2008)