The combined evico magnetics Kerr-Microscope & Magnetometer system is a facility for the visualization of magnetic domains and magnetization processes. It is a semi-automatic, contact-less, non-destructive measuring system using the magneto-optical Kerr effect in two versions:

(i) A low-resolution version allows to obtain an overview of the domain pattern of larger samples with a spot size of approx. 12 mm by 20 mm.

(ii) A high-resolution optical microscope allows for mapping of spot sizes between 100 μm and 5 mm and down to the resolution limit of optical microscopy (300 nm).

Both versions are implemented in the same setup and can be used optionally.




Features (excerpts):

Two optional versions of wide-field Kerr microscopes are implemented in the setup:

• Allows to obtain an overview of the domain pattern (or magnetization loop) of larger samples with a spot size of approx. 12 mm by 20 mm

• Separated illumination and reflection paths

• Rotatable polarizer, analzser and compensator module

• Allows observation down to resolution limit of optical microscopy (300 nm)

• High-end wide-field optical polarization microscope (Zeiss optics)

• Microscope head can be vertically shifted by approx. 150 mm to allow optional use of Version 1-microscope

• Objective lenses with magnificatons from 5x to 100x (oil immersion)

• Slit aperture for adjustable incidence

• Grid polarizer for increased Kerr-efficiency, rotatable by approx. 100°

• Rotatable analyzer and compensator module

• Highly stable intensive LED Lamp

• Consists of three LED modules with wavelengths that are optimized for maximum intensity. The wavelengths can be used individually or combined. Specific wavelengths on request

• Frame rate 8.8 - 43 frames/s (resolution dependent)

• Resolution maximum: 1.37 million pixel (1344 x 1024)

• Manually rotatble by approx. 360°

• Supported on a magnet holder with adjustable height, support independent from sample holder

• Water cooled

• In-plane field range from 10^-4 T up to 1.4 T

• Configurated workstation

• NI LabView based measurement software "KerrLab"

• Camera control

• Magnetic field control (DC, AC, demagnetization etc)

• Image processing capabilities for high contrast magnetic domain observation (real-time difference imaging technique)

• Recording of surface hysteresis loops (MOKE magnetometry) with simultaneous domain movement observation