Magnetooptical response of permalloy multilayer structures on different substrate in the IR–VIS–UV spectral range

Abstract

The magnetooptical (MO) response of Ru/Py/Ta thin film stacks with 4, 8, and 17 nm thick Ni81Fe19 permalloy (Py) films on a SiO2/Si and a ZnO substrate was measured by vector magnetooptical generalized ellipsometry. The MO response from VMOGE was modelled using a 4 × 4 Mueller matrix algorithm. The wavelength-dependent, substrate-independent and thickness-independent complex MO coupling constant ( Q ) of Py in the Ru/Py/Ta thin film stacks was extracted by fitting Mueller matrix difference spectra in the spectral range from 300 nm to 1000 nm. Although the composition-dependent saturation magnetization of Ni x Fe1−x alloys (x = 0.0…1.0), e.g. of Ni81Fe19, is predictable from the two saturation magnetization end points, the MO coupling constant of Ni x Fe1−x is not predictable from the two Q end points. However, in a small alloy range (0.0 < x < 0.2 and 0.8 < x < 1.0) the composition-dependent Q of Ni x Fe1−x can be interpolated from a sufficiently high number of analyzed Ni x Fe1−x alloys. The available complex MO coupling constants of six different Ni x Fe1−x (x = 1.0 to 0.0) alloys were used to interpolate MO response of binary Ni x Fe1−x alloys in the range from x = 0.0 to x = 1.0.

A versatile method for exploring the magnetooptical properties of polar saturated and unsaturated ferromagnetic metallic thin films

“…There are few reports in the literature on the MO properties of ferromagnetic materials and the design of multilayer structures with enhanced MO effects. In our previous work [14], we discussed that, compared with the MO response of multilayer structures with ferromagnetic metallic thin films having transverse and longitudinal magnetization, the MO response of multilayer samples with ferromagnetic thin films with polar magnetization is much larger. However, at the external magnetic fields available in MO experiments most ferromagnetic metallic thin films are only saturated for transverse and longitudinal configurations and are unsaturated in the polar configuration.…”

Analytical calculation of dielectric permittivity tensor from magneto-optical ellipsometry measurements

“…Numerical algorithms of data processing are proposed in a number of works, e.g. [6][7][8][9][10][11][12][13]. In the general case of anisotropic systems, the problem can be solved using 4 × 4 Mueller matrices [7][8][9][10][11][12][13][14][15].…”

“…[6][7][8][9][10][11][12][13]. In the general case of anisotropic systems, the problem can be solved using 4 × 4 Mueller matrices [7][8][9][10][11][12][13][14][15]. Some of these authors [9][10][11][12] decided to combine magneto-ellipsometry measurements with additional ex situ experiments, e.g.…”

“…In the general case of anisotropic systems, the problem can be solved using 4 × 4 Mueller matrices [7][8][9][10][11][12][13][14][15]. Some of these authors [9][10][11][12] decided to combine magneto-ellipsometry measurements with additional ex situ experiments, e.g. they used SQUID magnetometry to find out sample magnetisation, that is why they used another definition of dielectric tensor elements as well as of magneto-optical parameter.…”

“…they used SQUID magnetometry to find out sample magnetisation, that is why they used another definition of dielectric tensor elements as well as of magneto-optical parameter. They defined off-diagonal components of the tensor as ε xy = −iQ z M z where Q is called a thickness-independent complex magneto-optical coupling constant [9][10][11][12] which is assumed to be also magnetisation-independent. It is important not to confuse their definitions of the physical quantities with the conventional definition (1) which is used in this paper.…”