- Jan Fikáček: Magneto-optical Kerr effect measurements of various materials
- 2. 5. 2018, 14:30
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
Magneto-optical Kerr effect (MOKE) is a powerful tool for probing different surface magnetization states of magnetic materials. Generally, MOKE signals are directly proportional to surface magnetization components. Our relatively simple experimental setup allows to investigate small surface areas within 10-20 nm penetration depth. We can apply magnetic fields in two different directions and measure in a broad temperature range 2.9 - 400 K with simultaneous electrical resistivity measurements.
In the presentation I will show recent results obtained by our MOKE instrument located in the Institute of Physics. A special attention will be given to Heusler alloys, which belong to a wide group of materials studied for their possible applications in spintronics. For our NiMnGa single crystal, we can clearly identify magnetic domains reorientations, which are manifested via hysteresis loops in magnetic field scans [1, 2]. As another example we have found a good correspondence of our MOKE data with bulk magnetization measured on thin films of Rh2Mn5Bi4 prepared by magnetron sputtering. Another studied system was a single crystal of U4Ru7Ge6 with a similar agreement between MOKE and previously published results [3].
[1] J. Fikáček et al., Journal of Magnetism and Magnetic Materials 452 (2018) 373–379
[2] O. Perevertov et al., Physical Review B 95 (2017) 144431
[3] M. Vališka et al., Physical Review B 95 (2017) 085142