A mirror based polar magneto-optical Kerr effect spectroscopy arrangement

Area of Science:

• Condensed matter physics
• Materials science
• Spectroscopy

Background:

• Magneto-optical Kerr effect (MOKE) spectroscopy is crucial for studying magnetic thin films.
• Conventional polar MOKE setups often require specialized electromagnets with axial holes.
• Switching between polar, longitudinal, and transverse MOKE geometries can be cumbersome.

Purpose of the Study:

• To develop a versatile MOKE spectroscopy arrangement adaptable to conventional electromagnets.
• To enable easy switching between polar, longitudinal, and transverse MOKE geometries.
• To analyze and correct for signal artifacts introduced by the modified optical path.

Main Methods:

• Implementation of an additional mirror in the optical path for polar MOKE spectroscopy.
• Utilizing a standard C-frame or H-frame electromagnet without a pole piece hole.
• Theoretical analysis of photo-elastic modulation detection to understand signal mixing.
• Experimental validation of the theoretical model and demonstration of spectral correction.

Main Results:

• The proposed arrangement successfully performs polar MOKE spectroscopy using conventional electromagnets.
• Easy switching between polar, longitudinal, and transverse MOKE geometries is achieved.
• A theoretical analysis revealed and experimental results confirmed strong signal mixing between Kerr rotation and ellipticity due to the mirror.
• A correction procedure for the observed signal mixing was developed and applied.
• MOKE spectra of nickel films obtained with this setup align with literature values.

Conclusions:

• The described MOKE spectroscopy arrangement offers a practical and flexible alternative for studying magnetic thin films.
• The method simplifies polar MOKE measurements and enhances experimental versatility.
• The developed correction procedure ensures accurate spectral data despite optical modifications.