MOKE Results 137

Magnetic properties of CoMnGe ternary alloys Co Ge Mn Exhibits room temperature ferromagnetism in this entire composition range Shows a ridge of higher MOKE intensity  Related to the structural perfection ridge

Magnetic anisotropy: points on the ridge 5 th Point, Composition,=X, Y Six-fold (0  ) +Uniaxial (30  ) magnetic anisotropy 12 th Point, Composition,=X, Y

20th Point, Composition,=X, Y Magnetic anisotropy 26th Point, Composition,=X, Y

Model for Magnetic anisotropy Magneto-crystalline anisotropy Anisotropic energy in cubic crystals Demagnetization energy 0 MM M Additional term for the observed Uniaxial magnetic anisotropy

Asymmetric magneto-optic response Second-order terms -Contains transverse component of magnetization Where θ, is angle between M and H Due to the terms in the dielectric tensor second order in the magnetization The second-order term becomes the only important term in the case of perpendicular incidence! Osgood et al., Phys. Rev. B (1997) a, b depend on the optic geometry (polarization angle of the incident laser, analyzer angle and incident angle) and the dielectric tensor of the material

Model comparison r = th Point, Composition,=X, Y

Model comparison 20th Point, Composition,=X, Y

On the ridge 20th Point, Composition,=X, Y12 th Point, Composition,=X, Y 15 th Point, Stoichiometric

5 th Line comparison in transverse direction 2 nd on 5th 16th on 5th Intersection isotropic Uniaxial ratio-negative

12 th Line comparison in transverse direction 2 nd on 12th16th on 12thIntersection Uniaxial ratio-negativeisotropic

12 th line comparison in transverse direction 2 nd on 5th6 th on 5th Intersection Uniaxial ratio-negative Uniaxial ratio-positive

20 th line comparison in transverse direction 2 nd on 20th 16th on 20th Intersection Uniaxial ratio-negative