Versatile, high sensitivity, and automatized angular dependent vectorial Kerr magnetometer for the analysis of nanostructured materials

Abstract

Magneto-optical Kerr effect (MOKE) magnetometry is an indispensable, reliable, and one of the most widely used techniques for the characterization of nanostructured magnetic materials. Information, such as the magnitude of coercive fields or anisotropy strengths, can be readily obtained from MOKE measurements. We present a description of our state-of-the-art vectorial MOKE magnetometer, being an extremely versatile, accurate, and sensitivity unit with a low cost and comparatively simple setup. The unit includes focusing lenses and an automatized stepper motor stage for angular dependent measurements. The performance of the magnetometer is demonstrated by hysteresis loops of Co thin films displaying uniaxial anisotropy induced on growth, MnIr/CoFe structures exhibiting the so called exchange bias effect, spin valves, and microfabricated flux guides produced by optical lithography.

Plasmonic nanodevice with magnetic funcionalities: fabrication and characterization

“…Magnetization curves were obtained with a home-made Kerr magnetometer in longitudinal configuration, i.e., with the magnetic field applied in the plane formed by the incident and reflected beams and parallel to the sample plane ( [42][43][44]) as described in figure 2b. The system uses a 635 nm laser diode in p-polarization as light source.…”

High sensitivity detection of radio-frequency modulated magnetic moment in semiconductors

“…The spin polarization is usually detected by using optical techniques such as photoluminescence, 14 Faraday rotation, 15 or MOKE. 7 Electrical detection techniques based on spin-dependent injection across a semiconductor-ferromagnet contact 16 or spinHall effect 17 have also been demonstrated. However, to the best of our knowledge, the magnetic moment of the spin polarized electrons has not been directly measured since the signal is below the detection sensitivity of conventional instruments such as VSM or SQUID.…”

“…For example, a detection limit of 10 −21 Am 2 in unity bandwidth has been reported 6 for a ∼5 μm size SQUID sensor, but operating at a very low temperature of 125 mK. In contrast, optical detection methods such as magneto-optical Kerr effect (MOKE) 7 which have been used to investigate magnetic monolayers are more qualitative, since the absolute sensitivity depends on the sample studied, temperature, and the wavelength of light used. In all the quantitative detection methods, the sample is mechanically displaced or oscillated to suppress the background signal and enable the detection.…”

Scanning Magnetic Microscope Using A Hall-Effect Sensor for Images of Remanent Magnetization Fields

“…Most scanning magnetic microscopes require a cryogenic system, so their operation and maintenance are generally expensive, rendering them unfeasible for most low-cost laboratories [1][2][3]. Scanning magnetic microscopes using nonsuperconducting devices have recently been proposed in the literature, some of them for geological applications [4][5][6].…”