Ga1-x Mnx As /piezoelectric actuator hybrids: A model system for magnetoelastic magnetization manipulation

C. Bihler, M. Althammer, A. Brandlmaier, S. Geprägs, M. Weiler, M. Opel, W. Schoch, W. Limmer, R. Gross, M. S. Brandt, S. T.B. Goennenwein

Research output: Contribution to journalArticlepeer-review

69 Scopus citations


We have investigated the magnetic properties of a piezoelectric actuator/ferromagnetic semiconductor hybrid structure. Using a GaMnAs epilayer as the ferromagnetic semiconductor and applying the piezo stress along its [110] direction, we quantify the magnetic anisotropy as a function of the voltage Vp applied to the piezoelectric actuator using anisotropic magnetoresistance techniques. As the magnetic anisotropy in GaMnAs substantially changes as a function of temperature T, the ratio of the magnetoelastic and the magnetocrystalline anistropies can be tuned from approximately 1/4 to 4. Thus, GaMnAs/piezoelectric actuator hybrids are an ideal model system for the investigation of different piezoelastic magnetization control regimes. At T=5 K the magnetoelastic term is a minor contribution to the magnetic anisotropy. Nevertheless, we show that the switching fields of ρ (μ0 H) loops are shifted as a function of Vp at this temperature. At 50 K-where the magnetoelastic term dominates the magnetic anisotropy-we are able to tune the magnetization orientation by about 70° solely by means of the electrical voltage Vp applied. Furthermore, we derive the magnetostrictive constant λ111 as a function of temperature and find values consistent with earlier results. We argue that the piezo voltage control of magnetization orientation is directly transferable to other ferromagnetic/piezoelectric hybrid structures, paving the way to innovative multifunctional device concepts. As an example, we demonstrate piezo voltage-induced irreversible magnetization switching at T=40 K, which constitutes the basic principle of a nonvolatile memory element.

Original languageEnglish
Article number045203
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number4
StatePublished - 9 Jul 2008
Externally publishedYes


Dive into the research topics of 'Ga1-x Mnx As /piezoelectric actuator hybrids: A model system for magnetoelastic magnetization manipulation'. Together they form a unique fingerprint.

Cite this