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The out-of-plane magnetocrystalline anisotropy and magnetoelastic properties of series of epitaxially grown layers of Co2Fe0.4Mn0.6Si (CFMS) and Co2FeGa0.5Ge0.5 (CFGG) Heusler alloys thin films deposited on MgO with chromium buffer layer were investigated by means of the ferromagnetic resonance (FMR), SQUID magnetometer, and by the strain modulated FMR technique. The magnitude of the magnetocrystalline anisotropy constant was found to decrease with increasing layer thickness. The change of the anisotropy is caused mainly by the surface effects. However, for some of the samples series, the change of chemical ordering with the change of the magnetic layer thickness was also observed. An additional silver buffer layer influence on the properties of the magnetic layer was also investigated. For all three of the investigated series of the Heusler alloys, i.e., CFMS without Ag, CFMS with Ag, and CFGG, the experimentally observed magnitude of the magnetoelastic constant increases with the increase of the magnetic layer thickness.

The half-metallic Co 2 Fe 0.4 Mn 0.6 Si (CFMS) and Co 2 FeGa 0.5 Ge 0.5 (CFGG) Heusler alloys are representative materials showing high spin-polarization of conduction electrons.

The magnetoresistance and magnetization of multilayer Fe/Si and Fe/Ge films on GaAs were measured simultaneously as a function of magnetic field along the in-plane [ 1 1 0 ] and [ 1 1 ¯ 0 ] directions of the Fe. The field induced changes in the magnetoresistance and magnetization for each film are discussed in terms of the exchange coupling between the iron layers, and the thickness of the semiconductor spacer layer. The data show that there is exchange coupling across Ge spacer layers for layer thickness less than 1.2 nm.

Experimental data on uniaxial in-plane anisotropy field ( H K ) and magnetostriction ( λ s ) of the amorphous and nanocrystalline Fe 71.5 Cu 1 Nb 3 Al 2 Si 13.5 B 9 alloy obtained by ferromagnetic resonance (FMR) method are presented. The results are compared with those obtained by the transverse biased initial susceptibility method. The nanostructured phase was produced by means of thermal treatment (480–600 °C during 1 h) to develop the devitrification of the precursor amorphous material. The role of the Al enhancing the soft magnetic character with respect to the Al-free classical Finemet composition are also analyzed.

The transverse magnetization and longitudinal magnetization hysteresis loops of sputtered thin films of Fe/Ge and Fe/Si multilayers on GaAs(001) substrates have been studied. The dependence of the film magnetic anisotropy on the bilayer period and semiconductor composition was investigated using a MOKE magnetometer. The hysteresis loops were measured as a function of the angle between the applied magnetic field and the hard–hard axis of the film. For the longitudinal magnetization, the Fe/Si film loops had lower remanent magnetization compared to the Fe/Ge film with the same spacer thickness. Thus the Fe/Si film had stronger exchange coupling across the spacer layer compared to the Fe/Ge film. For the thicker Ge spacer layer film, no exchange coupling was measured. For the transverse magnetization, the Fe/Ge multilayer films loops had only one Barkhausen jump. For the Fe/Si multilayer films loops, some contained one Barkhausen jump while others had two jumps, due to the cubic anisotropy contribution. These results are interpreted in terms of anisotropy and exchange energies.

The Fe/Si multilayers structure was grown by direct current magnetron sputtering technique and was studied by means of X-ray photoelectron spectroscopy. The iron silicide formation at the oxidized Fe/Si interface is inhibited at room and elevated temperatures and it occurs at T ≥500 °C. The prolonged annealing of the Fe/Si interface to 500 °C leads to the steady growth of the Si 3+ and Si 4+ oxygen-related components in the sample.

The magnetic and transport properties of La1−xMn1+xO3 manganites with excess manganese are studied. It is shown that magnetic and charge ordering heavily depends on the superstoichiometric manganese content, magnetic field, and pressure. The magnetoresistive effect (MRE) is enhanced as the manganese concentration increases. In addition to the paramagnet-ferromagnet transition, the temperature dependences of the magnetization exhibit anomalies at low temperatures in samples with x=0.1–0.4. The magnetization decreases at T

The magnetic properties of Co 68 Mn 7 Si 10 B 15 glass coated amorphous microwires of about 16.5 μm in diameter have been investigated from liquid helium up to room temperature by ferromagnetic resonance at 9.243 GHz. Based on the results of measurements both the magnetic anisotropy constants, the first arising from the stress at the interface between the metallic surface and the coating and the second one of the inner core have been obtained for the room temperature. The effective anisotropy field was determined in the range from the liquid helium to the room temperature.

Measurements of ferromagnetic resonance (FMR) in both in-plane (H‖) and out-of-plane (H⊥) magnetic field configurations have been performed on a series of epitaxial (La0.7Ca0.3)1−xMn1+xO3 films. The FMR linewidths have a local maximum near the Curie point and increase continuously at low temperatures. The effective anisotropy of the films has the easy-plane character. The angular dependences of Hres were found to be in reasonable agreement with the theoretical ones, taking into account the second- and fourth-order terms of the magnetic anisotropy energy. A reasonable agreement between ΔHres(α) and Bloch type dissipation was obtained only for deviations of the external field from the normal to the film plane up to α=20°. From the temperature and angular dependences of the FMR spectra, the main magnetic parameters such as the effective magnetization, effective field Heff, anisotropy field HA2, and FMR linewidth were estimated.

The antiferromagnetic (AFM) interlayer exchange coupling for sputtered Fe/Si multilayers have been studied by magnetometry, wide-angle neutron diffraction, and spin-polarized neutron reflectometry. Ferromagnetic resonance and Raman scattering measurements have been applied for the characterization of the multilayers. To look for a possible modification of exchange coupling when Si is replaced by Ge, similar Fe/Ge multilayers have been prepared by the same technique. No AFM coupling has been found for Fe/Ge system. Present results differ in part from the literature data and suggest an influence of the sample preparation on the details of its magnetic properties.

Magnetization reversal of a Fe/Si/Fe trilayer having a ferromagnetic bilinear and biquadratic exchange is investigated at 10 and 300 K. The experiments were performed using the magneto-optical Kerr effect technique and a SQUID magnetometer. The type of stable magnetic configuration is determined for both temperatures of the study. The hysteresis loops contain jumps in magnetization, which could be associated with the overcoming of the energy barriers related to the uniaxial anisotropy hard axes in the two iron layers. The analysis of the experimental results was performed in the framework of a model in which the ferromagnetic bilinear and biquadratic exchange between two magnetic layers separated by a nonmagnetic spacer and the cubic and uniaxial anisotropy were taken into account. Good qualitative agreement is obtained between the experimental and calculated field dependences of the magnetization.

Magnetostriction measurements were performed at different temperatures for Fe81Si3.5B13.5C2 METGLAS® films using a strained substrate technique. The magnetostriction constant was deduced from magnetic properties measured using a vibrating sample magnetometer. The film strain was varied using a range of curved sample holders. From the change of magnetic anisotropy field as a function of controlled strain, the saturation magnetostriction constant can be determined with sufficient accuracy. The temperature dependence of magnetostriction of METGLAS® Fe81Si3.5B13.5C2 from 9 to 287 K is reported. It is suggested that a single-ion mechanism of magnetostriction is dominant in this amorphous alloy.

The magnetic anisotropy and magnetoelastic properties in epitaxial iron films prepared by DC magnetron sputtering on single crystal GaAs (001) substrate and covered by a protective Si layer have been investigated by means of the ferromagnetic resonance (FMR), strain modulated ferromagnetic resonance (SMFMR) and magneto-optical Kerr effect (MOKE). It has been shown that the uniaxial and cubic anisotropy constants as well as two magnetoelastic constants strongly depend on the thickness of the film. The surface parts of the cubic anisotropy and magnetoelastic constants have been obtained.

The magnetization reversal of a multilayered Fe/Si film having cubic magnetocrystalline anisotropy is investigated in the temperature interval 25–300 K by magnetooptical methods. It is found that the growth of the biquadratic exchange interaction as the temperature is lowered causes a spontaneous second-order phase transition from a collinear antiferromagnetic state to a noncollinear state. The presence of cubic anisotropy in the film gives rise to spontaneous and magnetic-field-induced first-order phase transitions between noncollinear states. Magnetooptical studies permit constructing the H–T magnetic phase diagram of the multilayered Fe/Si film for an orientation of the external field along the hard magnetization axis [110]. A calculation of the H–T phase diagram in the framework of a model taking into account the bilinear exchange and cubic anisotropy, with constants I1 and K that are assumed to be independent of temperature, and also the biquadratic exchange with a linearly temperature-dependent cons...

Magnetostrictive FeCo films (thickness 300 nm) have been produced by RF magnetron sputter deposition. The effects of the substrate, composition and thermal treatment on the structural and magnetic properties of the films have been determined. Structural analysis was performed using transmission electron microscopy and x-ray diffraction. The magnetic properties, including magnetostriction, were determined by the magneto-optical Kerr effect, magnetic force microscopy and strain-modulated ferromagnetic resonance. It is found that the magnetic softness of the films is critically dependent on the texture and strain state of the film. With suitable choices of substrate, composition and thermal treatment, these parameters can be controlled, producing magnetically soft films while maintaining a high magnetostriction. The differential response of the magnetic anisotropy to strain in these films is comparable to the best values achieved by more involved manufacturing processes, such as multilayering, showing excellent potential for their use in magnetic sensors and actuators.

Magnetization reversal processes in Fe/Si multilayered films have been studied by means of the longitudinal magneto-optical Kerr effect at room temperature. The multilayers have been grown by DC sputtering on the single-crystal GaAs substrate. The Kerr effect curves had areas with an invariable or slightly varying rotation and had different remanent rotation value in the zero magnetic field for different directions of the magnetic field in the film plane. The observed features are related to the formation of stable and metastable noncollinear spin configurations. The experimental results are explained in the framework of the theory, which takes into account the competition between the bilinear exchange term on the one hand and the biquadratic exchange or cubic magnetic anisotropy terms on the other hand.

Nitriding thermochemical treatment under suitable parameters is used to nano-crystallize Fe73.5Cu1Nb3Si13.5B9 ribbon. This new kind of treatment leads to finer nano-structure and modifies the structural parameters of the α-Fe(Si) phase, obtained during the treatment. The magnetic properties are also improved; specific magnetization at room temperature and Curie temperature of the crystalline phase increase, and the magnetostriction constant becomes smaller. The nitrogenation seems to offer a new way to obtain nanostructured ribbons. PACS No.: 75.70

Fe73.5Cu1Si13.5B12 and Fe73.5Cu1Nb3Si13.5B9 nanocrystallized amorphous ribbons are investigated. To obtain the nanocrystalline state, a new kind of treatment is performed: nitriding thermochemical treatment (NTT). We show that this treatment can slightly improve the nanocrystalline state compared to the conventional thermal treatment (CTT). The new treatment leads to smaller grain size and higher crystalline volume fraction. It increases the Curie temperature of the crystalline α-FeSi phase and leads to smaller values of the magnetostriction constant.

Magnetization processes in thin Gd/Fe multilayer films have been studied by means of the longitudinal magneto-optical Kerr effect and magnetization measurements. Comparison between magneto-optical and magnetic measurements allows one to conclude that a field-induced surface spin reorientation occurs in the studied films for a magnetic field applied in the film plane. The experimental results can be satisfactorily interpreted in the framework of the developed theoretical model. This model predicts a formation of a noncollinear magnetic structure within the gadolinium surface layer during the process of the field-induced spin reorientation phase transition.

Rapidly quenched alloy of nominal composition Co 68 Nb 10 B 30 Cu 2 has been chosen as the parent material for nanocrystalline magnets exhibiting Curie temperature of the residual amorphous matrix much lower than room temperature. Characteristic feature of these magnets is that the created ferromagnetic crystals are embedded in the paramagnetic amorphous matrix for the measuring temperatures in their relatively very wide range between both Curie points of the residual amorphous matrix and the crystals. Crystallization and microstructural properties of a series of the nanocrystalline magnets produced at different temperature of annealing have been studied and the results obtained are shown. Similarly, basic magnetic properties of the nanocrystalline samples are also presented. The main conclusion drawn is that the magnets considered are suitable for the studies of magnetic properties of the crystals themselves and their mutual interaction through paramagnetic matrix, in particular.

A reinforcement of the ferromagnetic character with applied tensile stress has been found in Fe 86 Zr 7 Cu 1 amorphous alloy with a linear relationship between the change of the magnetization per unit stress. By annealing with electric current, an improvement of the magnetic softness of the alloy can be achieved in the range of current density of 50 to 75 Axmm −2 . Such an effect is connected to the presence of ultrafine grains of dimensions typically of nanometers. Results of the magnetostriction constant are also reported for the as-quenched and nanocrystalline alloy which are interpreted in terms of surface and bulk contributions from α-Fe grains.

FMR measurements in various magnetic field geometries have been performed on the La 0.63 Ca 0.27 Mn 1.1 O 3 film. The H res (T)dependence is well described by the Brillouin function. Taking into account the magnetic anisotropy of higher order improves the agreement between theoretical and experimental H res (α) dependences. The experimental ΔH res (α) dependence agrees with theoretical one at the deviation of magnetic field from the normal to the film plane up to α ∼15°.

Results are presented from magnetic and magnetooptical studies of the magnetic configurations in a three-layer film Fe(30 A)/Si(14 A)/Fe(30 A) in which ferromagnetic and biquadratic exchange between iron layers is observed and which also possesses cubic and uniaxial anisotropy. These studies were done at temperatures of 300 and 10 K. It was found that in the absence of magnetic field a noncollinear magnetic structure, the form of which changes with temperature, is observed in this system. A calculation of the stable noncollinear configurations is done on the basis of a model in which it is assumed that both the exchange interaction constant and the cubic and uniaxial anisotropy constants in the iron layer change with temperature. The values of the angles characterizing the magnetization direction in the iron layers in the stable noncollinear configurations are determined on the basis of a comparative analysis of the experimental data and the results of the calculation. It is shown that both the angle betw...

Ferromagnetic resonance (FMR) and dc-magnetometry measurements were used to investigate the temperature dependence of the anisotropies responsible for the exchange-bias coupling in NiFe/FeMn bilayer. At room temperature, both measurements showed the same exchange-bias angular distributions due to a low coupling strength, ${H}_{\text{E}}$, with respect to the antiferromagnet domain-wall formation anisotropy. The anisotropies derived from both techniques displayed identical ${H}_{\text{E}}$ values but different uniaxial anisotropies. This disagreement may be ascribed to different stabilities of antiferromagnetic grains in both techniques. At low temperature, strong disagreements were found on the exchange-bias values. They are explained by the occurrence of the slow relaxer mechanism in FMR experiments.

Nitriding thermochemical treatment (NTT) is used as nanocrystallization method. Such a method slightly improves the nanocrystallization state of Fe 73.5 Cu 1 Si 13.5 B 9 (Nb 3 ) and Fe 73.5 Cu 1 Si 13.5 B 9 (Zr 3 ) alloys in comparison with the conventional method. The magnetostriction constant obtained either with Nb- or Zr-addition to the FeCuSiB-system is lower than that obtained when the sample is annealed conventionally.

We report on the temperature dependence of ferromagnetic resonance (FMR) measurements on NiFe/FeMn bilayer. This includes investigations about the angular distribution of the resonance, ${\text{H}}_{\text{R}}$, and that of the linewidth, $\ensuremath{\Delta}\text{H}$. By considering the domain-wall formation model, the exchange-bias field, ${\text{H}}_{\text{EB},\text{FMR}}$, is derived from the FMR measurements. The disagreements observed at low temperature between these values and the ones obtained from superconducting quantum interference device measurements, ${\text{H}}_{\text{EB},\text{SQUID}}$, are discussed. We demonstrate that the negative line shift and the maximum of the linewidth of the FMR line are both perfectly interpreted through the slow-relaxer mechanism. This enabled us to elucidate the intriguing question about the yielding to different values of the exchange-bias anisotropy by both techniques.

Nitriding thermochemical treatment under suitable parameters, used to nanocrystallize Fe–Cu–Nb–Si–B ribbons, leads to finer grain size and modifies the structural parameters of the α-Fe(Si) phase: low Si content, probably due to the formation of Si–N precipitates on a very fine scale. Furthermore, both the specific magnetization of the alloy and the Curie temperature of the crystalline phase increase upon nitrogenation and the magnetostriction decreases in relation with the higher crystalline volume fraction. It is shown that nitrogenation offers a new method to obtain nanostructured materials.

An effective coupling field between ferromagnetic sublayers was found as a function of the thickness t of the non-magnetic medium in multilayered structures of FeBSi/Si and FeBSi/Pt. The surface energy anisotropy constant was also determined for FeBSi/Pt films. We used ferromagnetic resonance and spin wave resonance at room temperature for the study of the properties of multilayered structures of metallic glasses of FeBSi separated by silicon or platinum. Thin films were obtained by the r.f. sputtering technique. Some basic magnetic parameter such as saturation magnetization and exchange constant were found from the ferromagnetic and spin wave resonances of single films of metallic glasses. The additional anisotropy field of the effective coupling is of the easy-plane type when silicon is the non-magnetic medium for t greater than 1.5 nm. For platinum, the effective field exhibits an easy-axis anisotropy along the film normal and the surface anisotropy constant varies from sample to sample in the range from 0.2 to 0.6 erg cm−2. We also observed a weak t dependence of the surface anisotropy field.

The energy constant Ks of surface anisotropy was determined for amorphous films of Co1−xZrx. Surface mode excitation in a Spin Wave Resonance (SWR) experiment at X-band was used to derive Ks. The Surface Inhomogeneity (SI) model with the symmetrical boundary conditions for the surface spins was applied to calculate Ks. The energy of surface anisotropy is given as Es = −Ks cos2θM where θM is the angle between magnetization and the film normal.

It is shown that progressive crystallization of non-magnetostrictive Co-based metallic glass (VITROVAC 6030) leads to an increase of coercivity by more than three orders of magnitude. The mechanisms responsible for this phenomenon are interpreted showing that the main source for the giant increase of the coercivity is the pinning effect on the domain walls originating from the created crystallites of the size much smaller than the domain width (correlation length for ferromagnetic exchange interactions). It is also shown that gradually devitrified non-magnetostrictive metallic glass is an excellent model material for verification of Neel's theory describing the Rayleigh rule.

Results are presented on the evolution with the thermal treatment parameters of the effective anisotropy and dispersion fields and of the saturation magnetostriction of samples having nominal compositions given by Fe93−xZr7BxCuy (x=6–8 and y=0–2). From these data we conclude that the enhancement of the soft magnetic character of the samples induced by the anneals carried out in the temperature range 480–600 °C could be linked both to the decrease of the anisotropy field and to the reduced magnetostriction values resulting from the thermal treatments.

X-ray, neutron powder diffraction (NPD), and magnetic measurements were performed in order to investigate the effect of Pr substitution for La on crystallographic structure, on character of magnetic ordering, and on transition temperature in ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Pr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3+\ensuremath{\delta}}$ manganites series $(0\ensuremath{\leqslant}x\ensuremath{\leqslant}1.0)$. Strong dependence of structural and magnetic properties on average $A$-site ionic radius was found. The magnetic phase diagram, characterizing Pr concentration dependence of the phase transition temperature, was constructed, based on magnetic and on NPD results. In the compounds with $xl0.7$, the ferromagneticlike behavior with ferromagnetic moment aligned along the $b$ axis was observed in the temperature interval below the Curie temperature, ${T}_{\mathrm{C}}$, varying in the range of $113--153\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, down to Mn ions canted spin arrangement transition temperature, ${T}_{\mathrm{CANT}}$, varying in the range of $73--115\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. It was found that ${T}_{\mathrm{C}}$ changes nonmonotonously with Pr content, it decreases rapidly for $xl0.3$ and for $xg0.6$, while is practically independent on $x$ for $0.3lxl0.6$. The Mn magnetic moments increase from 3.2 for $x=0$ to 3.6 for $x=0.3$ before decreasing to $1.7\phantom{\rule{0.3em}{0ex}}{\ensuremath{\mu}}_{\mathrm{B}}∕\mathrm{Mn}$ for $x=1.0$ and form a canting structure with canting angle decreasing from 32\ifmmode^\circ\else\textdegree\fi{} for $x=0$ to 16\ifmmode^\circ\else\textdegree\fi{} for $x=0.3$ and then increasing to 70\ifmmode^\circ\else\textdegree\fi{} for $x=1.0$. The NPD and x-ray diffraction data indicate that Pr doping in $\mathrm{La}\mathrm{Mn}{\mathrm{O}}_{3}$ is accompanied by changes of both the lattice parameters and crystal structure. The compound with $x=0$ was shown to have a rhombohedral crystal structure, while the samples with $0.1\ensuremath{\leqslant}x\ensuremath{\leqslant}0.6$ have orthorhombic symmetry with a small Jahn-Teller distortion (or pseudocubic) which continuously transforms towards highly distorted orthorhombic structure for $xg0.6$. From ac magnetic susceptibility, studied under hydrostatic pressure up to $1.5\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$, it was found that ${T}_{\mathrm{C}}$ and ${T}_{\mathrm{CANT}}$ change linearly with an applied pressure. The results are interpreted taking into account the competition of ferromagnetic double-exchange and antiferromagnetic superexchange interactions. This competition leads to a low temperature disordered system with spin canted features as a result of a decrease of the average $A$-site cation radius followed by decrease of Mn-O bond lengths, Mn-O-Mn bond angles, and the static Jahn-Teller distortion of the $\mathrm{Mn}{\mathrm{O}}_{6}$ octahedra.

A comparison of field dependences of the meridional Kerr effect and magnetization leads to the conclusion that a noncollinear inhomogeneous magnetic state is formed in the surface layer of gadolinium in multilayered Gd/Fe films in a magnetic field. Experimental results are described by using a theoretical model predicting the formation of a noncollinear spin configuration in the surface Gd layer as a result of a spin-reorientation phase transition induced by the magnetic field.

The effective magnetic anisotropy and saturation magnetostriction of both amorphous and nanocrystalline (samples with different microstructures) Fe/sub 83/Zr/sub 7/B/sub 8/Cu/sub 2/ alloy have been investigated. The effective anisotropy results were obtained through the measurement of the bias field dependence of the transverse susceptibility in samples annealed from 480 to 600/spl deg/C. In the above mentioned range, the annealing temperature dependence of the saturation magnetostriction is related to the presence of a nanocrystalline structure leading to a remarkable magnetic softening. From our results it was possible to discern the occurrence of intergranular coupling and to evaluate the typical dimensions of the coupled units.

Commercially available Fe‐Co alloys with Co contents of 50 and 24 wt. % have been rf sputtered to produce multilayers with noble metal (Ag or Cu) interlayers. Series with fixed Fe‐Co or noble metal thicknesses have been produced, as have plain Fe‐Co films. In all cases, the coercivities of the multilayers are significantly reduced from those exhibited by the plain alloy films. For example, a film of the alloy containing 50 wt. % Co had Hc=6.9 kA m−1, whereas a multilayer with 12 nm Fe‐Co layers and 2 nm Ag layers had Hc=480 A m−1. The saturation magnetostriction is also enhanced, in some cases increasing by 60% over the expected bulk polycrystalline alloy value. For example, the literature λs value for a Fe‐Co alloy containing 24% Co is about 28 ppm; in a multilayer with 12 nm alloy layers and 8 nm Ag layers, λs=45 ppm. The combination of high magnetostriction and low coercivity makes such materials as these attractive for their potential as stress sensor and actuation transducer elements.

The coherent anisotropy and the magnetostriction constants /spl lambda//sub s/ were studied in amorphous RF sputtered (Co/sub 93/Zr/sub 7/)/sub 100-x/(RE)/sub x/ (RE=rare earth) thin films for a large variety of magnetic rare earth, and the concentration range 0/spl les/x/spl les/3. During the deposition magnetic field of 700 Oe was applied in the film plane. For RE=Nd, Pr, Dy and Tb substitutions, a well defined in-plane uniaxial anisotropy is formed. K/sub u/ and /spl lambda//sub s/ both increase linearly with increasing RE content, the absolute values being related to the substitutional RE element. The magnitude of K/sub u/ correlates nicely with that of /spl lambda//sub s/, in agreement with a theoretical computation based on a single-ion anisotropy model for rare-earth atoms. When RE=Sm a more heterogeneous local magnetic structure forms as revealed by a biaxial anisotropy and the correlation between K/sub u/ and /spl lambda//sub s/ is no more observed. >

Current device technology requires high magnetostriction in low-coercivity, low-anisotropy samples. It has long been suspected that surface interfaces provide a method for tuning the magnetostriction. In this paper we explore the effects of a surface configuration in granular iron-cobalt silver systems. Significant reduction is seen in the granular material, which can not be explained simply by theory or in terms of the surface to volume ratio. A detailed discussion is made of the possible effects.

Magnetoelastic tensor components M/sub 11/ and M/sub 12/ for Ni/Ti multilayers are measured at room temperature using strain modulated ferromagnetic resonance (SMFMR). The dependence of M/sub 11/ and M/sub 12/ on the inverse Ni layer thickness is interpreted as 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. >

The results of magnetostriction constant λ s of multilayer Fe/C sputtered films are reported. The measurements have been performed at room temperature using strain modulated ferromagnetic resonance method. The structure of films is amorphous, mixture of amorphous and cubic and purely cubic. The magnetostriction constant λ s is different for any phases and depends linearly on the inverse of the Fe layer thickness.

In the Gd/Fe multilayers, the magnetic moments of the ferromagnetically ordered layers of Gd and Fe lie in the film plane and are oriented antiparallelly due to antiferromagnetic exchange interaction at the interface. It is known that a magnetic field applied in the plane of such film induces the phase transition to the twisted state [1–4]. The collinearity of the magnetic moments of Gd and Fe layers is destroyed at the transition. The spin reorientation to the twisted phase originates from the surface of the Gd/Fe multilayers if the magnetic moment of the outermost layer is opposite to the field direction [3,4]. In the present paper, the other type of the surface spin reorientations induced by a magnetic field has been found in the Gd/Fe multilayers terminated with the Gd layer. A magnetic field induced a noncollinear spin configuration within the outermost Gd layer of multilayer.

Experimental and theoretical research on magnetoelastic properties of magnetic superlattices is reviewed. The importance of interfaces and the occurrence of surface magnetoelastic effects is emphasized. It is shown that the dependence of effective magnetostriction on the magnetic layer thickness is due to the magnetostrictive strains localized at the interface.

The influence of the dipolar interaction on surface magnetostriction is presented. The ferromagnetic film is considered as a set of discrete atomic dipoles neatly ordered in the film. This consideration is limited to simple ferromagnets of high symmetry as body centered cubic (BCC) and face centered cubic (FCC) with

Low-temperature properties of thin iron films prepared by DC magnetron sputtering on single-crystal GaAs (0 0 1) substrates have been investigated by means of FMR measurements. It was found in the presence of both the fourfold and twofold anisotropy. Both of them depend strongly on the thickness of the film. It means that the surface anisotropy determines not only the value of the twofold anisotropy but also the fourfold one.

The FMR and SQUID investigation of the magnetic anisotropy of Fe/Si multilayers are presented. The multilayers, with various thicknesses of iron and a thick layer of silicon (in order to eliminate the coupling between Fe layers), have been grown by DC sputtering on single crystal GaAs substrates. Low temperature enhancement of the easy-plane anisotropy, especially below 50 K, was observed. This anisotropy seems to be of magnetoelastic origin. The coercivity was shown to decrease with temperature.