Characterization instrument DXMOKE

Overview

The DXMOKE series Surface Magneto-optic Kerr Effect System is an integrated optical measurement platform for quantitative characterization of Kerr rotation and ellipticity on magnetic thin films, nanostructures and spintronic devices. It provides hysteresis loops and magnetic parameters such as coercive field and saturation field, and is configurable for in-situ and low-temperature studies.

Features of DXMOKE Surface magneto-optic Kerr effect system

• TTL modulation of a low-noise laser source for stable optical excitation.
• High-sensitivity photodetector tube to capture light-intensity changes.
• Lock-in amplifier for frequency-locked signal acquisition and improved signal-to-noise ratio.
• Low-noise, high-resolution and thermally stable measurement performance.
• Highly integrated optical assembly: straightforward sample mounting and fine adjustment of the sample rod to obtain Kerr signals with minimal alignment.
• Combined Kerr measurement and magnetic-domain observation microscope with 6 µm spatial resolution.
• Options for in-situ vacuum measurements and multiple magnetic-field and cryogenic configurations.

Basic functions

• Single-point loop measurements: longitudinal, transverse and polar Kerr configurations.
• Area mapping: precision XY stage for MOKE mapping at multiple positions on the sample surface.
• 360° rotation of sample or magnetic field to identify easy/hard magnetization axes and measure anisotropy.
• Sample holder with electrical interface available for magnetoelectric and transport coupling tests.
• Integrated high-speed CCD and microscope for surface observation; with an optional polarizer, enables polarization-state-dependent intensity imaging to obtain magnetic domain contrast.

Technical specifications

• Kerr angle resolution: < 0.001°.
• Ellipse (ellipticity) resolution: < 0.1%.
• Minimum spot size: 10 µm.
• Maximum magnetic field: 2.2 T (with EM7 electromagnet option).
• Rotation angle step: 0.1°.
• XY stage displacement step: 10 µm.
• Noise level: < 1%.
• Cryogenic option: temperature range 100 K – 300 K; temperature control accuracy ±0.01 °C; cooling time to 100 K ≈ 30 min; heating rate 0.01 – 30 °C/min; sample measured in vacuum; K9 glass optical window to minimize magneto-induced optical rotation.