There is an increasing interest in metallic multilayers as novel properties can be achieved in them. Magnetic multilayers of Co/Pt and Ni/Pt have been synthesized with varying bilayer thickness to investigate associated magnetic properties. Our earlier studies have shown that both Co/Pt and Ni/Pt multilayers grown in ultra high vacuum evaporation system exhibit uniaxial magnetic anisotropy perpendicular to thin film plane. This is however possible for ultra low thicknesses of Co or Ni. Magnetization in Co is large compared to that in Ni for same thickness regimes. It is further noted that magnetic moment is induced on Pt in Co/Pt multilayers, whereas no induced magnetization occurs for Ni/Pt multilayers. X-ray Photoelectron Spectroscopy of growing interfaces is carried out in order to understand the differences between these two multilayers.

CoFe2O4/ZnFe2O4 bilayers were deposited by the pulsed laser deposition on amorphous fused quartz substrate at substrate temperature of 350°C and in oxygen pressure of 0.16 mbar. The films were studied after ex-situ annealing for 2 h in air at various temperatures up to 650°C. The magnetic properties of the bilayers were studied at 300 K and at 10 K. Ferromagnetic resonance was carried out at x-band frequencies at room temperature. It was found that as a result of annealing, the diffusion between Co ferrite and Zn ferrite starts around 350°C and leads to a large line width system having magnetization, which remains undetected by Ferromagnetic resonance.

The magnetic anisotropy results of Ni/(Au, Ag and Cu) multilayers, prepared by sequential evaporation in ultra high vacuum, were described on the basis of existing models. It is shown that magnetoelastic anisotropy energies K me of the Ni/(Au, Ag and Cu) multilayers which have fcc (111) perfectly flat interfaces can be expressed with biaxial modulus, magnetostriction and lattice mismatch. In the incoherent state, the residual strain gives rise to a magnetic anisotropy which is proportional to the reciprocal of the magnetic layer thickness. The influence of roughness would decrease the anisotropy contribution.

The paper reports on magneto-optic Kerr spectroscopy in a series of [αFe2O3/NiO]2.5 multilayers and NiFe2O4 films at the photon energies ranging from 1.2 to 4.5eV. The samples were prepared by pulsed laser deposition onto fused quartz substrates. The thickness of layers and the diffusion of Ni and Fe ions at interfaces were controlled by choice of the conditions of deposition and subsequent annealing. The magneto-optical response of the model system [αFe2O3/NiFe2O4/NiO]2.5 (where interdiffusion is simulated by formation of ferrimagnetic NiFe2O4 interlayer) is determined by means of matrix calculation based on Yeh formalism and compared with experimental data. From the analysis of polar Kerr rotation spectra of NiFe2O4 single layers we denoted possible structural defects in these layers.

We prepared NiOαFe2O3 multilayer films by pulsed laser ablation. Interdiffusion leads to the formation of the nickel ferrite NiFe2O4 at the interfaces. Its ferrimagnetism provides a local probe on the admixture of the antiferromagnetic oxides NiO and αFe2O3 which is macroscopically measurable. We performed magnetization, torque and magnetooptical measurements on the multilayer samples. Several phenomena were observed. As a function of the substrate temperature a kinetically (due to the incoming particle energies) and a thermally activated regime of NiFe2O4 formation were observed. In the thermally activated regime, the duration of the deposition per layer and therefore the temperature dependent diffusion at the interfaces plays a crucial role to the formation of the ferrite as can be seen from the magnetic moment m which tends to saturate for long in-situ annealing times. Surprisingly, an oscillation of m as a function of the number of interfaces was observed for the NiOαFe2O3 multilayer films. This indicates a magnetically and perhaps structurally non equivalence of the NiOαFe2O3 and the αFe2O3NiO interfaces. This oscillation is observed in the magnetization, the Faraday and the coercive fields.

In this paper, we report the study of the magnetic properties of (Li 0.5-x/2 Mu 0.1 Zu x Fe 2.35-x/2 O 4 ) films with x=0, 0.16, 0.32, 0.48. The films were deposited on fused quartz substrates by rf sputtering technique under various deposition conditions. The magnetic properties of the films annealed at 750°C are being reported. The M a values of the films deposited at a rf power of 240 W in argon atmosphere were found to be smaller than the corresponding bulk values. The M a value was found to be maximum at x=0.32, similar to the bulk. The H c values of the films are much higher than the bulk values and decrease as a function of x.

We have prepared CoxNi1−x/Pt multilayers by evaporation under ultrahigh vacuum conditions and studied their magnetic and magneto-optical properties. Addition of Co to Ni increases the surface anisotropy and TC. For instance, in Co0.3Ni0.7/Pt for t(Co, Ni) = 4.5 Å, one observes a perpendicular rectangular M-H loop with a coercivity of 800 Oe and TC of 180°C. The polar Kerr rotation of this sample shows a peak value of 0.3° at the photon energy of 4 eV. These characteristics are very interesting for realising magneto-optic storage media capable of working in blue light.

The complex polar Kerr effect spectra (Kerr rotation and Kerr ellipticity) of high-purity ferromagnetic nickel are reported in the spectral range 1.5–5.2 eV. Freshly evaporated high optical quality Ni films, 90 nm thick, magnetically saturated perpendicular to the film plane served as sample surfaces. New extended spectroscopic information has been obtained. The agreement with the published data is discussed.

Up to now, the cubic spinel CoFe2O4 was assumed to have a collinear ferrimagnetic structure; however a High Field Mössbauer Study (HFMS) recently evidenced for canting angles at both A and B iron sites. In order to have a coherent view on the CoFe2O4 magnetic structure, we performed high field magnetic measurements and neutron diffraction experiments on the same powdered sample, already used in the HFMS. Neutron diffraction shows unambiguously a long range ferrimagnetic collinear structure (T = 300 and 5 K). All the experimental results are coherent in a model of non-uniform canting (local order).

Magnetoelastic tensor components M11 and M12 for Ni/Ti multilayers have been measured at room temperature using strain modulated ferromagnetic resonance (SMFMR). The dependence of M11 and M12 on the inverse Ni layer thickness is interpreted as arising mainly due to anisotropic volume and isotropic interface interactions. It is suggested that the SMFMR method provides the possibility of distinguishing between intrinsic surface magnetostriction and interdiffusion effects.

Co/Pt multilayer films have been prepared by evaporation under UHV conditions. For samples with Co layer thickness below 0.8 nm rectangular loops are observed. While the polar Kerr rotation decreases with the Co layer thickness, the Faraday rotation, on the contrary, is seen to increase strongly. This increase has been attributed to the presence of Co-Pt alloy layer formed by maxing at the interfaces and whose thickness has been estimated to be about 0.3 nm. Furthermore this layer is thought to play a crucial role in the origin of the uniaxial anistropy. Faraday rotation study is thus shown to be an useful tool to characterize the multilayers.

The complex polar magneto-optic Kerr spectra at the photon energy range 1.5 to 5.2 eV in amorphous TbxFe1-x films with 0.15 ≤ x ≤ 0.23 rf sputtered onto water cooled glass substrates and covered by Al2O3 layer, are presented. They extend the previously published data to higher photon energies where the combined effects of the enhancement by the Al2O3 and the oxide layer created at the metal dielectric interface and those of 4f-5d electronic transitions of terbium become important. An explanation of the spectra is proposed based on the knowledge of the Tb effect in iron garnets.

We report on our magnetic studies of amorphous (Fe1−x Erx)80B12Si8 ribbons with 0

The complex polar Kerr spectra of ferrimagnetic garnets and spinels have been studied in the spectral region from 2 to 6 eV. The influence of Ga, Al, In, Sc, Pr, Sm, Tb and Ho on garnet spectra is presented and discussed. The reflectivity and dielectric tensor element spectra were also obtained for selected samples and the data is then used in the explanation of the spectra in terms of charge transfer transitions. In particular the bands near 3.4, 3.6, 4.3 and 4.7 eV are respectively assigned to the transitions to t 2g , e, t 2 and e g orbitals. The effect of polishing on reflectivity spectra of lithium ferrite is briefly discussed.

The complex Kerr and reflectivity spectra of Y 3 Fe 5 O 12 and Li 0.5 Fe 2.5 O 4 and the reflectivity of Y 3 Fe 4.6 Sc 0.94 O 12 and Y 3 Fe 3.9 - Ga 1.1 O 12 are studied in the spectral range 2.0–6.0 eV. The results suggest that in this range, the majority of transitions involve 3-d states of Fe 3+ ions. The dominant role is played by the tetrahedral Fe 3+ ions.

A simple procedure is presented for computing optical transmission and Faraday-rotation optical density (OD) planar layered structures when all internal reflections are taken into account. The procedure makes use of the Mueller matrix technique and assumes that interference effects, Faraday ellipticity, and boundary magneto-optical effects, e.g., Kerr effect, are not important. The general formulas are applied to the case of the three-layer structure from which two examples of some practical interest are derived, i.e., a single absorbing layer on a nonabsorbing substrate and two identical absorbing layers on either side of a nonabsorbing substrate. The solutions are substantially simplified when Faraday-rotation angles are small.

physica status solidi (a)Volume 17, Issue 1 p. K65-K68 Short Note Optical and magnetooptical properties of epitaxial YIG films R. Krishnan, R. Krishnan Laboratoire de Magnétisme, C.N.R.S., Meudon–BellevueSearch for more papers by this authorH. Le Gall, H. Le Gall Laboratoire de Magnétisme, C.N.R.S., Meudon–BellevueSearch for more papers by this authorTran Khanh Vien, Tran Khanh Vien Laboratoire de Magnétisme, C.N.R.S., Meudon–BellevueSearch for more papers by this author R. Krishnan, R. Krishnan Laboratoire de Magnétisme, C.N.R.S., Meudon–BellevueSearch for more papers by this authorH. Le Gall, H. Le Gall Laboratoire de Magnétisme, C.N.R.S., Meudon–BellevueSearch for more papers by this authorTran Khanh Vien, Tran Khanh Vien Laboratoire de Magnétisme, C.N.R.S., Meudon–BellevueSearch for more papers by this author First published: 16 May 1973 https://doi.org/10.1002/pssa.2210170156Citations: 19AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume17, Issue116 May 1973Pages K65-K68 RelatedInformation