Magneto optical Kerr effect

An increasingly important tool to determine the strain-induced anisotropy is MOKE (magneto-optical Kerr effect). In section 2 we mentioned already the calculations by Freeman et al. (1999). Experimentally, e.g. Ali and Watts (1999) (see also references therein) apply a bending device to induce strains in a controlled way, and determine the (local) curvature and the strains by optical interferometry or by direct measurement (stylus). The properties of the substrate are incorporated in a finite-element modelling calculation, thus allowing an absolute determination of the film properties. Compare also Stobiecki et al. (2000), who studied the strain induced anisotropy in FeB/Cu/FeB trilayers, using Kerr magnetometry (MOKE). 

Magnetic thin films of nickel-iron (usually deposited at an 80 20 composition by weight) exhibit a number of unusual properties, which have led to many experimental and theoretical studies, as well as to impoitant applications in binary storage and switching, magnetic amplifiers, and magneto-optical Kerr-effect displays,... 

For optimum performance, CD measurements require a polarization modulated source. In principle, any of the polarization-selective optical devices discussed earlier could be mechanically moved to create the required modulation. However, this approach is problematic in that it is difficult to implement physically, the mechanical movement may introduce noise into the measurement situation, and there are limitations to the rate at which the polarization can be modulated. A preferable approach is to use an electronic device to effect the required phase retardation. Although a number of devices have been used for this purpose (e.g. magneto-optical, Kerr effect, etc.), modern CD instruments rely upon either the Pockels effect, or photoelastic modulation for this function. 

The geometrical arrangement indicates the relationship to the magneto-optical Kerr effect (MOKE). MCDAD corresponds to the longitudinal, MLDAD to the transversal MOKE. Additionally, the Earaday effect can be included it is the analogue to the magnetic circular dichroism in absorption (XMCD). 

Fig. 7.7 Saturation field as a function of the V layer thickness for AF coupled Fe(3)/V(x) superlattices, obtained by magneto-optic Kerr effect and SQUID measurements. The thicknesses which are accessible by loading the samples with hydrogen are marked by arrows in the figure. Taken from Hjorvarsson et al. (1997), ref [38].

When applied in surface investigations, this effect is also called surface magneto-optical Kerr effect (SMOKE) [661]. 

SMOKE Surface magneto-optical Kerr effect... 

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