Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 15: Poster:ThinFilms(1-33),Transp.(34-49),ExchBias(50-56),
Spindynamics(57-70),Micro-nanostr.Mat.(71-82),
Particles/Clust.(83-88), Mag.Imag./Surface(89-96),
Spinelectronics(97-109), Theory/Micromag.(110-116),
Spinstruct/Phasetr.(117-128),Magn.Mat.(129-139),
Aniso.+Measuring(140-145), MolMag.(146-152),
MSMA(153-156)
MA 15.32: Poster
Dienstag, 27. März 2007, 15:00–19:00, Poster A
Tunable strain in MgO single crystals — •Mathias Weiler, Andreas Brandlmaier, Stephan Geprägs, Matthias Opel, Sebastian T. B. Goennenwein, and Rudolf Gross — Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
Crystalline strain affects many properties of solid state materials, e.g. the electronic band structure or the magnetic anisotropy of ferromagnets. The application of controllable strain thus is interesting for the realization of multifunctional materials. We discuss how the expansion of a piezoelectric actuator alters the strain in a MgO crystal at room temperature. Using two-component epoxy, we glued a 2× 2× 0.1 mm3 piece of a (001)-oriented MgO single crystal onto a piezoelectric actuator. The main elongation axis of the actuator is aligned in the platelet plane, along a MgO [100] direction. We measure the modification of the MgO crystalline structure as a function of the voltage Vpiezo applied to the actuator, using high-resolution x-ray diffraction. From 2Θ-ω scans, we find that the MgO lattice constant c along [001] (perpendicular to the platelet plane) can be linearly and reversibly tuned by up to Δ c/c=3×10−5 upon applying −30 V≤ Vpiezo≤ +90 V. According to elasticity theory, this implies that only about 10% of the actuator stroke is transferred into the MgO crystal. We discuss this observation, and compare our results to the effect of Vpiezo on the magnetic anisotropy of Fe3O4 thin films grown onto MgO and then attached to a piezoelectric actuator.