VŠB-TU Ostrava

Laboratory of magneto-optical Kerr microscopy

Measuring method:

Magneto-optical Kerr microscopy for observation of magnetic domains at surfaces of materials, domains are investigated at room temperature in static magnetic field.

Laboratory equipment:

Optical microscope Zeiss, Xe lamp, optical components (polarizer, analyzer, lens, filters), objectives with different magnifications, CCD camera Hamamatsu, magnets generating magnetic field in the sample plane and perpendicular to the sample plane, power supply Kepco, software Kerrlab, antivibration table, CMOS camera, two indicator garnet films on transparent substrate with mirror at the backside (magneto-optical indicator films).

Investigated materials:

Solid ferromagnetic and ferrimagnetic materials (low surface roughness is necessary) – thin films, multilayers, amorphous and nanocrystalline materials based on Fe, Co and Ni.

Investigated properties of materials:


Tab. 1 Objectives EC Epiplan-Neofluar Pol and their parameters

Objective magnification x/numerical apertureSize of viewing field [mm]Ideal resolution
2,5x/0,06 3,600 x 2,7206100
10x/0,25 0,900 x 0,6801464
20x/0,50 0,450 x 0,340732
50x/0,80 0,180 x 0,136457
100x/0,90 0,090 x 0,068406

Tab. 2 Used magnets

Magnetic field generated along the sample surface
Air coil,
gap distance 38 mm
Hmax = 32 kA/mI = 4 A
Poles for lower field
poles gap 25 mm
Hmax = 280 kA/m
Poles for higher field
poles gap 12,5 mm
Hmax = 480 kA/m
Magnetic field generated perpendicularly to the sample surface
Cylindrically symmetric magnet Hmax = 288 kA/mI = 4 A

Laboratory of magneto-optical Kerr microscopy
Laboratory of magneto-optical Kerr microscopy