Berlin 2005 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

MA: Magnetismus

MA 20: Poster:Schichten(1-29),Spintrsp(30-45),Ex-Bias(46-63),Spindyn(64-75),Mikromat.(76-80),Cluster(81-94),Abbv.(95-99),Obflm(100-02),SpElek.(103-09),E-Theo(110-14),Mikromag.(115-16),Spin+PÜ(117-26),Mag.Mat.(127-51),Meth.(152-55),Mol.Mag(156-59),Kondo(160-65

MA 20.74: Poster

Monday, March 7, 2005, 14:00–18:00, Poster TU C

Near-field imaging of magnetic nanostructures with high lateral and temporal resolution — •Gereon Meyer, Andreas Bauer, Andreas Goris, and Günter Kaindl — Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin-Dahlem

Magnetic-domain patterns can be imaged with high magnetic contrast, sub-wavelength lateral resolution and in the presence of external magnetic fields by utilizing a scanning near-field optical microscope in combination with a Sagnac interferometer (Sagnac-SNOM), which measures the magneto-optical Kerr effect [1,2]. One major advantage of magneto-optics is the ability to study magnetization dynamics on ultrashort time scales. We report on first test measurements of time-resolved magneto-optical SNOM based on Sagnac interferometry: In a stroboscopic measurement, a femtosecond pulse of a frequency-doubled Ti:sapphire laser is split into two counter-propagating pulses of different intensity. One of them is used as pump pulse that optically excites the sample, the other, delayed one, probes the sample with a variable time delay. The non-reciprocal phase shift between the two pulses is a measure of the transient magnetization [2]. In this way, we intend to monitor spin-precessions in ultrathin films with a lateral resolution of < 150 nm.

[1] G. Meyer et al., Appl. Phys. Lett. 83, 1394 (2003).

[2] G. Meyer, A. Bauer, and G. Kaindl, Near-Field Imaging of Magnetic Domains, in: Progress in Nano-Electro Optics IV, M. Ohtsu (ed.) (Springer, Berlin, 2005).