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The optical properties of copper Cu-Ni compound metal island (CMI) films composed of nanoclusters of an alloy of Cu and Ni have been experimentally investigated. The spectral characteristics of the Cu-Ni CMI films are intermediate between those of conventional Cu and Ni island films in visible and near-IR regions. In addition, the magneto-optic effect has been observed in the Cu-Ni CMI films. It is also shown that the Faraday rotation in the Cu-Ni CMI films can easily be controlled by selection of the mixture ratio of Cu and Ni. OCIS codes: 310.0310, 230.3810, 230.2240.

An apparatus has been constructed for the practical realization of the Cotton-Mouton effect in colloidal suspensions. Measurements of the magnetically induced birefringence in such media, using a medium power argon-ion laser operating at a wavelength of 515 nm, have been made for variable magnetic field intensities up to 2.5 T. Data have been recorded on the four pure liquidsv - nitrobenzene, carbon disulphide, acetone, and benzene. The system has been primarily designed for studies on colloidal media for which the Cotton-Mouton effect can be large, thereby requiring relatively low intensity magnetic fields. Data for bentonite and vermiculite are reported, which demonstrate the ease and validity of such measurements for colloid characterization. These are the first known data on suspensions of vermiculite clay. Furthermore, the influence of any stray Faraday effect is examined. Index Terms - Coilloids, magnetic birefringence, optical anisotropy, magnetooptics, susceptibility anisotropy.

Magnetic garnet films are grown by liquid phase epitaxy which support lattices of parallel stripe domains. The domain resonance and the domain wall resonance are excited at GHz frequencies using rf magnetic fields of proper polarization. The excited lattice acts as dynamic phase grating and can thus be applied for modulation of light. Two geometries are steadied: (i) Optical modes propagate in the waveguiding film, modulation is achieved by dynamic mode conversion. (ii) Light passes the film perpendicular to the film plane and is modulated by diffraction. The modulation efficiencies are measured as function of the static induction applied in the film plane parallel to the stripe domains. From the experimental data the precession angles and the wall oscillation amplitudes are derived. The possibility of dynamic deflection of optical modes is discussed.

Performance of magneto-optic isolators is often limited by the properties of the Faraday rotator, which can be improved. 1) A compensation point layer can be used to control the temperature dependence of the material and consequently improve the extinction ratio to [greater than or equal to] 30 dB from -10 [degrees] C to 85 [degrees] C without significant increase in device size or complexity. 2) Variation of composition and lattice parameter can decrease the material absorption and therefore the device insertion loss at specific wavelengths. 3) Development of a 'latching' Faraday rotator material with an effective coercivity above 1 kOe allows the design of devices with no bias magnet and consequently lower cost and size.

Finite-difference beam propagation for integrated optical isolators and circulators is simulated. Mode propagation in magnetropic waveguides which distinguishes between the backwards and forwards directions is used in such devices. This is analyzed by two different directions of the waveguides magnetization. The practical creation of nonreciprocal integrated optical components and their consequences are considered.

Study of the magneto-optical properties of Ba-ferrite particulate media reveals that the media's magneto-optical output is maximum at a particular thickness. The study involves the measurement of the magnetic reflectivity and Faraday rotation for various thicknesses of the magnetic layer. The equations which approximate toward the Faraday rotation and reflectivity help explain the influence of thickness on the magneto-optical output.

The new reflected mode magneto-optic spatial light modulator contains a film-embedded conductor and narrow drive lines to enhance optical efficiency and pixel switching sensitivity. Small pixels generate a high resolution in the modulator to increase the frame rate and decrease the optical path length. The new modulator, used in computers and optical correlators, is more effective than the transmission mode modulator.

The Faraday effect and the magneto-optic Kerr effect are measured by a Sagnac interferometer which utilizes two optical beams which have the same path in opposite directions for measurement. This technique provides the ability to determine the magnetization vector in a region and measures magneto-optic effects in the absence of an external field.

High surface energy for sputter etching of polymer substrates with oxygen gas is comparable to that of a glass substrate. The magneto-optical properties of ultrathin Co/Pt multilayers deposited on polymer substrates are improved compared to those deposited on glass. A chemical reaction having oxygen atoms is attributed to the increase in the surface free energy due to sputter etching.

Amorphous rare-earth-transition-metal (RE-TM) alloys containing Pr, Nd, Fe and Co are prepared by coevaporation and their magnetic and magneto-optical properties are analyzed with respect to their compositional behavior. RE and TM influence the-magneto-optical properties, and at high temperatures, TM has more influence. The Faraday and Kerr relations for Pr-TM and Nd-TM alloys are larger for temperatures below the curie temperature.

The faradaic response of a slow electron transfer to a triple pulse of potentials was derived for the planar approximations of a static mercury drop electrode and the dropping mercury electrode. The analytical solution obtained for a static mercury drop electrode is subject to no constraints in the time interval over which the different potentials are applied. The effects of the formation of the double layer have not been taken into account in the mathematical treatment. The solution obtained was verified by comparising of the analytical solution to experimentally measured i--t curves for some completely reversible, completely irreversible, and quasi-reversible processes, namely the reduction of Cd(II), Cr(III), and Zn(II), respectively. The use of a triple pulse of potentials to develop new voltametric and polarographic techniques, improving on the performance of double-pulse techniques, is discussed. Among these we propose the double differential pulse (DDP) technique which involves using the current function [i.sub.1] - [2i.sub.2] + [i.sub.3] where [i.sub.j] is the current corresponding to potential pulse [E.sub.j]. We also propose the square well pulse (SWP) technique which relies on the current function [i.sub.3] + [i.sub.2] - [2i.sub.1] for a time ratio [t.sub.2]/[t.sub.3] = 0.283. Finally, the solution for the previously reported reverse differential normal pulse (RDNP) technique was obtained. The features and performance of these techniques are discussed., The faradic response of a slow electron transfer to a triple pulse of potentials for the planar approximation to the behavior of voltammetry and polarography is analyzed. Solutions corresponding to the third pulse of potentials were obtained from previously derived second pulse solutions and were verified by its comparison to the experimentally measured i-t curves of cadmium, chromium and zinc. New voltammetric and polarographic techniques were developed from thestudy.

The principle of measuring magnetic fields with a ring laser system is discussed. The main source of error, the Zeeman effect, is studied, and a corresponding technique to reduce it is described. An experimental setup is developed with a Faraday cell of a large product of the Verdet constant and the length. The experimental device obtains a sensitivity of 0.5 nT and a stability of 2 nT.

A study was conducted to analyze the interfacial magnetic characteristics of NiFe/Al/Al2O3 heterostructures as a function of Al2O3 thickness and processing conditions. The thin films were prepared by sputter deposition onto oxidized silicon substrates. The second-harmonic magneto-optic Kerr effect was utilized to carry out the analysis. Experimental results indicated the effectiveness of the Kerr effect in evaluating tunnel junction quality during processing.

An equation was developed to explain the magnetic circular dichroism sum rules in terms of the complex dielectric tensor. Using classical Maxwell-Fresnel theory, the equation was employed for the reflection spectra of Fe at the M(sub 2,3) transition to compute the orbital moments. Analysis indicated that because of the energy dependence of the unpolarized normalization integral and the absence of a well-defined cut-off energy across the transition edge, large errors can be introduced.

The influence of the [Pr.sup.3+] substitution on the magnetic and magneto-optical properties of YIG is analyzed by using the quantum theory. The temperature dependence of [Pr.sup.3+] magnetic moment is calculated, in the 4.2-300 K temperature range. The Faraday rotation (FR) and Faraday ellipticity spectra at photon energies between 0.8 and 6 eV are determined as well. It is shown that the [Pr.sup.3+] contributions to FR and to the magnetic moment depend strongly on the splitting of the [4f.sup.2] configuration induced by the crystal field and Fe-Pr superexchange interaction. The resonance frequencies are mainly determined by the splitting of the 4f5d configuration. The good agreement between the calculated and measured values of both the magnetic and magneto-optical properties proves the correctness of the model and of the parameters used.

Simulated magnetooptical images of domain walls are compared quantitatively with direct observations. The simulation is based on a micromagnetic model of V-lines in (110) oriented iron, a linear theory of magnetooptical diffraction and image formation based on Fourier optics.

We present evidence that domain-wall pinning in MnBi films is responsible for the unusual increase of the high- temperature coercivity. The MnBi crystallite size has been reduced by depositing Bi/Mn/Al multilayers. The average diameter of the MnBi particles is smaller than the critical diameter of single-domain particles, therefore, domain-wall pinning does not enhance the high-temperature coercivity as observed for pure MnBi films.

The mechanism of the MO effect for the [Mn.sub.50][Sb.sub.44][Pt.sub.6] film was discussed from the viewpoints of the structure and optical properties. As results, it was clarified; (1) the [Mn.sub.50][Sb.sub.44][Pt.sub.6] film after annealing at 300 [degrees] C was found to consist of MnSb with the ordered NiAs phase and PtMnSb with the disordered f.c.c. phase. (2) The resonancelike MO Kerr effect at about 2.1eV was the unique character only for the [Mn.sub.50][Sb.sub.44][Pt.sub.6] film. (3) For the [Mn.sub.50][Sb.sub.44][Pt.sub.6] film after annealed at 300 [degrees] C the maximum of [[Theta].sub.K] at around 2.1eV, where [[Epsilon].sub.xx][prime] was relatively small, was originated from [[Epsilon].sub.xy][prime].

We have studied the magneto-optical Kerr effect (MOKE) of air-annealed Co thin films. Structural investigations reveal the formation of a double layered Co oxide (fcc [Co.sub.3][O.sub.4]) / Co metal structure. MOKE spectra, measured in the photon energy range 0.8 [less than or equal to] [E.sub.Ph] [less than or equal to] 5.5 eV, show characteristic changes as function of the annealing time and temperature. In particular, we observe the occurrance of resonance type enhancements with peak Kerr rotations of [[Theta].sub.K] = -5.5 deg. The experimental spectra can be quantitatively reproduced using bilayer optical stack calculations.

The magneto-optical spectra of chemically ordered FePt (001) and FePd (001) compounds are studied. The imaginary part of the off diagonal element, [[Sigma].sub.2xy] of the conductivity tensor has two peaks located in the energy ranges 1.2 - 2 eV (Fe-like transitions) and 4 - 4.5 eV (Pt or Pd like transitions). The strength of these peaks is larger in FePt than in FePd and roughly scales with the spin orbit coupling of Pt and Pd d-bands in the ultraviolet spectral range. Large differences in the Fe dominated low energy side of the spectra suggest a much higher degree of electronic hybridization in FePt than in FePd.

Calculations of the weak one-magnon light scattering and Stokes and anti-Stokes scattering in antiferromagnet MnF2 as a function of temperature show a dominant linear magneto-optical coupling coefficient for in-phase scattering while the quadratic in-phase coefficient also makes a marked contribution. Theoretical results of the evaluation of temperature and polarization dependences of Raman intensities agree well with experimental data.

The Kerr microscope studies the variation of magnetic domain structure (MDS) with the carbon diffusion from CH4 gas into Sm2Fe17 coarse powder by using the magneto-optical polar Kerr effect. The incompletely carburized grains cause structural variations, indicating the presence of carbon concentration profiles. Changes in magnetic anisotropy and spontaneous magnetization occur due to this change in the MDS. During diffusion, the grains crack, enhancing the carburization process.

Experimental studies of the magnetooptical and electrical transport properties of Fe/Cr/Fe magnetic trilayers show that a 2-monolayer (2-ML) oscillation period characterizes the magnetoresistance of the trilayers. Antiferromagnetic properties of the Cr interlayer are responsible for the periodicity. The magnetoresistance loops of the trilayers reveal specific steps that reflect the magnetic field values responsible for altering magnetization.

In situ investigation of the magnetic anisotropy of Ni films on Cu(100) by surface magneto-optic Kerr effect reveals the existence of the easy axis of magnetization in the plane of the film for ultrathin films, while the axis is perpendicular to the film above a switching thickness. The presence of magnetocrystalline anisotropy above a critical thickness is responsible for this behavior. Magnetoelastic interface anisotropy in Ni/Cu(100) system prefers perpendicular magnetization, similar to shape anisotropy at the switching thickness.

Pt level deficiency increases coercivity and adjustment in rapid thermal processing (RTP) time and composition regulates the crystalline texture of the PtMnSb films. Coercivity is independent of the crystalline texture and dependent on formation of MnSb stages in the PtMnSb films. Coercivity is independent of the crystalline texture and dependent on formation of MnSb stages in the PtMnSb microstructure. Pt deficiency reduces polar Kerr rotational properties in the films.

Transverse (TKE) and longitudinal (LKE) magnetooptical Kerr effect measurements in thin magnetic films reveal the magnetic field and spin value effect (SVE)-dependent magnetization reversal in the films. Transitions between the easy axes of the field in the films influence the reversal process and measure anomalous resistance as functions of applied magnetic field.

The design of phase-optimized Co/Pt-based trilayer structures to magneto-optically improve the polar Kerr effect was delineated. The device performance was determined as a function of the incident radiation wavelength and incidence angle for the two polarization states. The trilayer structure design scheme used Co-Pt multilayers as the magnetic medium.

Substitution of small concentrations of Fe in barium ferrite thin films by Co, Mn, Cr and Ni in using a multitarget scanning cosputtering process and rapid thermal processing results in enhanced magneto-optical properties as indicated by significant increase in polar Kerr rotation at shorter wavelengths. The magnetic properties remain unaltered in the case of Co and Ni substitution. Mn and Cr reduced the magnetic anisotropy.

Molecular beam epitaxy facilitated the growth of Co-rich Au/Co multilayers, whose ellipticity and magneto-optical polar Kerr rotations were studied. The demagnetization energy of these multilayers was greater than the perpendicular magnetic anisotropy. An increase in interface participation reduced the individual layer thickness to a few atomic monolayers.

Magnetron sputtering onto Si(111) substrates produces Al- and Bi-doped DyIG/Fe multilayered thin films. The layers range in thickness from 50 to 130 angstroms and 5 to 15 angstroms, respectively. The crystallization of these garnet layers occurs when the layers are rapidly annealed. Well-defined interfaces are exhibited by the crystallized multilayer samples.

The magneto-optic and magnetic properties of Co/Ni multilayers deposited on Au and Ag buffer layers exhibit perpendicular magnetic anisotropy. The magnetic anisotropy of multilayers with Ag buffer layers is negligible. The perpendicular magnetic anisotropy is dependent on the degree and structure of crystalline alignment of the buffer layers.

The antiferromagnetic (AFM) and ferromagnetic (FM) exchange coupling in molecular-beam-epitaxially grown (MBE) wedged trilayers are determined by applying room temperature polar magneto-optic Kerr effect (MOKE) measurements at high fields. The polar MOKE of Co/Cu/Co(111) exhibits an AFM coupling peak at 9 angstroms copper thickness. Another AFM coupling peak is exhibited at 20 angstroms. This reveals that oscillatory couplings exist in (111)-oriented MBE grown films.

The theory of enhanced magneto-optical effect in YBiFeO12, based on the covalent reactions of Bi(super 3+) and Fe(super 3+) ions, is validated by molecular orbital estimates of excited-state spin-orbit coupling multiplet splitting experiments. The application of self consistent approximation to the bonding-antibonding hybrid helps determine the splitting energies.

Interlayer thickness produces an intensity oscillation of saturation polar Kerr rotation in sandwiched films of Fe/Au/Fe. Each layer is about six angstroms thick. The periods of oscillation are 7 to 8 and 5 to 6 for each monolayer of gold. The oscillations are in the photon energy range of 2.5 to 3.8 electron volts.

Intermetallic alloys such as Mn5(GeM)3, where M is Sn or Pb, are experimentally investigated to determine the magnetic and magneto-optic properties. The alloys exhibit ferromagnetic ordering at temperatures less than 300 K. The hexagonal phase describes the structure of Mn5(GeSn)3. The Curie temperature and the magnetization are extremely high and are associated with room temperature polar Kerr rotation.

Facing targets sputtering apparatus is used to prepare amorphous Tb-Fe-Co/M bilayers. The method involves Kr sputtering and the bilayers possess an internal stress of 1 multiplied by 10 to the power 9 dynes per square centimeter. A Kerr rotation angle of 0.85 degrees is exhibited by Tb-Fe-Co/Ta.

MnBiSi films subjected to favorable doping indicate a structural distortion. The structure and magneto-optical properties of the effect of Al doping on these films are analyzed. The structural distortion is caused by the doping of Al and an increase in the Kerr rotation angle.

Magneto-optical Kerr effect studies in ultrathin cobalt films reveal the temperature-dependent sharp maximum of the ac susceptibility to be related to ferromagnetic-paramagnetic phase transition at Curie temperature Tc. Magnetic properties of the films in paramagnetic regions above Curie temperature are also measured by this method.

Three-axis surface magneto-optical Kerr (SMOKE) effects techniques investigating the switching behavior of Fe/Cu(100) thin films indicate the presence of canted stimulated uniaxial anisotropy in the out-of-plane complex of the film. Rotational processes of SMOKE indicate the cubic anisotropy of in-plane complexes at 45 degrees orientation in the films.

Surface magneto-optic Kerr effect techniques monitor the growth of ultrathin ferromagnetic films and the amplitude and frequency varying hysterisis loops in a dynamic scaling pattern. Low frequency and amplitude values narrow the loop area to a power law form. The scaling function and measured exponents agree well with theoretical and computational Monte Carlo techniques.