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X-ray diffraction experiments in pulsed magnetic fields are used for studying the giant magnetic-field-induced strain in the martensitic phase of ordered [Fe.sub.3]Pt alloy. The results have shown that the magnetic-field-induced strain associated with the rearrangement of the variants has occurred in a very fast sweeping pulsed field.

The results of quantitative analysis of fluorescence x-ray absorption fine structure (XAFS) experiments at the Fe-K absorption edge are presented for a 6*(4.3 nm Fe/10.4 nm Al) multilayer prepared by pulsed laser deposition. The results indicate that by conventional XAFS measurement at fixed angle of incidence, an Al content of the first two coordination shells of each Fe atom of about 58 at. % Al was obtained averaged over the entire Fe layer.

Research was conducted to examine the x-ray photoemission and absorption spectroscopy of supported nanoscale iron clusters. Fe clusters deposited onto two substrates were characterized using x-ray photoemission sppectroscopy, x-ray absorption spectroscopy and magnetic linear dichroism. Results show that the magnetic dichroism signal of the exposed clusters increases sharply with the film thickness due to the increased cluster interactions.

A study on the semiconducting phase of iron disilicide, beta-FeSi2 in relation to thermoelectric conversion applications was conducted to measure the Hall effect and electrical resistivity of Fe(sub 1-x)Mn(sub x)Si2 between 80 K and 300 K to clarify the mechanism of electrical conduction in Mn-doped beta-FeSi2. The ionized impurity scattering mechanism is used to explain the temperature dependence of the mobility of Fe(sub 1-x)Mn(sub x)Si2 at high temperatures.

A study was conducted to analyze the quantum size and composition effects on the optical characteristics of Fe(sub x)Zr(sub 1-x)O2 clusters using measurements of the photoacoustic spectra at room temperature. The Japan Rigaku x-ray diffractometer was utilized to obtain x-ray powder diffraction patterns. The aerogel cluster powders were then formed by the gelation of the precursor chemicals. Results indicated that iron doping of ZrO2 powders results into strong subgap absorption in the ZrO2 grains.

Scanning tunneling microscopy in air is used to investigate the grain structure and interatomic distances in annealed Hf2Fe and in annealed and nonannealed Hf2Co polycrystalline isostructural phases with Ti2Ni type. The findings indicate a phase transition in morphological transformations during the annealing of Hf2Co. They also suggest that the more resolved charge distribution of Hf2Fe is more 'metallic' and that similar behavior of valence electrons of the ions in Fe(Co) explains the similar intensities of the bright spots indicating the characteristic positions of Hf and Fe(Co) under the same scanning conditions.

The electrical resistivity and Hall effect of Co-doped and Ni-doped beta-FeSi2 were quantified in the temperature range between 80 and 300 K. The results showed that the solid solution Fe1-xCoxSi2 is n type over the entire temperature range investigated, whereas the solid solution Fe1-yNiySi2 exhibited n type characteristics at temperatures beyond 160 K and p type tendencies below 160 K. At 300 K, the carrier concentration of Fe1-xCoxSi2 is one level higher than that of Fe1-yNiySi2.

Measurement of low temperature transport and magnetic properties of the filled skutterudite CeFe4Sb12, an advanced thermoelectric material, shows that the thermal conductivity decreases sharply compared to unfilled skutterudites due to the presence of the cerium atom in the lattice. The reduction in thermal conductivity is related to phonon scattering from the rare earth atom. The electrical resistivity, Hall coefficient, thermoelectric power and magnetic susceptibility of the skutterudite resemble those of heavy fermion-like systems.

Use of magnetic measurements and x-ray phase analysis to investigate the magnetic properties and structures of R2(Fe(1-x)Si(x))17 compounds reveals that Si substitution for Fe in the compounds causes a phase transition to occur at x = 0.2. The mean iron magnetic moment is inversely proportional to the Si concentration. The exchange interaction constant A(FeFe) of the compounds is directly proportional to the value of x.

Examination of the critical exponents of the Ising model of FexMg(sub 1 - x)Cl2 using finite size scaling and the Monte Carlo histogram method indicates the deviation of the critical exponents due to superexchange between planes and a small degree of frustration. The pure system exhibits three dimensions, while additional disorder reduces critical divergences in the dilute system. The diluted system does not behave like the random field Ising model.

bcc Polycrystals, with grain size of 17 nanometers and short range order characteristic (SRO) of the DO3 ordered structure, constitute the AS-prepared films of Fe-21.5 at. % Ge. The crystals are determined by Mossbauer spectroscopy. Relaxation of film stresses and development in SRO are caused by continuous annealing to high temperatures. This also caused a reduction in magnetic coercive field.

Magnetic properties and microstructure are investigated as a function of lamination period in 1-(mu)m thick FeAIN/Al (sub 2)O(sub 3) multilayers. It is proposed that the deposition mode employed is responsible for the lack of canting exhibited in the grains of films deposited onto tilted substrates due to a reduced directional anisotropy of the particles impinging the substrate.

The increase of the magnetoresistance could be caused by the same effect, which causes the increase of magnetoresistance of the pure MnAu(sub 2) at low temperatures. Smith and Street suggested explaining this effect by varying densities of electronic states at the Fermi level in the ferromagnetic state.

The study presented shows that partial chemical ordering can be obtained at moderate processing temperatures by using post growth ion bombardment. The changes on the magnetic hysteresis loops are compatible with the expected perpendicular magnetic anisotropy increase.

The interlayer exchange coupling and the magnetic structure of bcc (001) Fe/Cr multilayers are studied using a first-principles self-consistent tight-binding linear-muffin-tin-orbital method in the atomic sphere approximation. In addition, it is found that for certain Cr thickness, incommensurate spin density waves with different wavelengths coexist.

The sense layer thickness in a recording head whether spin-valve decrease so that the sense layer can be effectively saturated by the transitions on the media. It was found that the softness of the CoFe free layer was improved when sandwiched by Cu layers, showing similar soft properties and magnetostriction to conventional free layers.

The effect of Ta and Ta/Cu seed layers, and Ta and Cu cap layers on the effective magnetic thickness of ultrathin permalloy (Ni(sub 81)Fe(sub 19)) was investigated for magnetic random access memory (MRAM) applications. Experimentally, it was shown that the tantalum rather than the copper interfaces are primarily responsible for the magnetically dead layers.

Fabricated NiFe wires partially covered by CoSm pinning pads are studied, and the resistance between the no-wall state and the wall-existing state at zero fields is compared. It was found that the resistance is smaller when magnetic domain walls exist, and the domain wall resistance is almost temperature independent.

Epitaxial Fe(sub 34)Co(sub 66) films in a thickness range from 3 to 100 monolayers (MLs) were grown by molecular beam epitaxy on GaAs(100) at room temperature. The growth was characterized by reflection high energy electron diffraction and x-ray diffraction.

The biquadratic exchange coupling in epitaxially grown Fe/Si/Fe is studied. Biqudratic coupling in Fe/Si/Fe can be understood in terms of Slonczewski's loose spins model.

The writing performance of narrow trackwidth single pole heads was studied on double layer perpendicular media. The MFM study suggests that the deep submicron track width single pole head exhibits a potential for achieving a recording density of more than 50 Gbit/in (super 2).

Polycrystalline Ga-substituted Pr(sub 3)(Fe (sub 1-x)Co(sub x))(sub 27.5)Ti(sub 1.5 (x=0.3,0.4) magnets are studied for high temperature permanent magnets. Scanning electron microscopy and energy dispersive x-ray analysis measurements inducated the 3.29 phase as the majority phase.

Results concerning linear variable differential transformer (LVDT) displacement measurements using Fe (sub 77.5)Si(sub 7.5)B(sub 15) amorphous wires as movable core are presented. The LVDT presents small dimensions, high sensitivity, good mechanical and corrosion resistance, the most important application being in the cases where low inertia of the active core is of great importance.

Thick, adherent films of Nd-Fe-B are deposited on substrates of copper and sheet steel using a low-pressure plasma-spraying process. Controlling the temperature profile of the system is one of the most important issues to obtain dense deposits with excellent magnetic properties and good bonding to the substrate.

Surface-energy-induced secondary or tertiary recrystallization by grains with a specific surface plane can be freely governed in thin gauged 3% Si-Fe strips by controlling the bulk content of sulfur and annealing atmosphere. During a vacuum or hydrogen annealing process, a convex profile in segregated-sulfur concentration is formed which corresponds to a trough in magnetic induction.

The effects of addition of carbon on structure and magnetic properties of the Sm(sub 20)Fe(sub 70)C(sub 10) alloy synthesized by mechanical alloying are investigated. The Sm(sub 2)Fe(sub 14)C and alpha-Fe phases tend to form when more carbon is added.

The spin reorientation transitions are found for all of these compounds, and the spin-reorientation temperature decreases with increasing Co content. The Curie temperature increases strongly with increasing Co content.

A detailed study of the complex inductance response of as-cast CoFeBSi wires as function of frequency (100 Hz-13 MHz range) and circular field amplitude [0.1-17A/m room mean square (rms) on the surface of the wire] in the giant magnetoimpedance arrangement is presented. In addition, a detailed analysis of real and imaginary parts of inductance leads to a characterization of the involved magnetization processes.

The intergrain exchange magnetic coupling through the amorphous boundaries in the two-phase Fe-based nanocrystalline alloy is described. The thermal evolution of the soft magnetic property and magnetic anisotropy is suggested to be responsible for the high-temperature giant magnetoimpedance features.

Laser ablation arrays of triangular and square shaped clusters, comprised of 23 (mu)m diam circular holes are defined upon 100 nm thick Ni(sub 81)Fe(sub 19) films. A nonlinear increase in the number of cluster-to-cluster domain walls occurs at cluster-to-cluster domain spacing between 275 and 300 (mu)m.

Bonding at the ferromagnet-insulator interface is an important factor which influences spin polarization of the tunneling current in ferromagnetic tunnel junctions. The Fe/O atomic structure is optimized using the plane-wave code CASTEP within the spin-polarized generalized-gradient approximation.

Inelastic-electron-tunneling (IET) spectra for the Ta/Fe(sub 20)Ni(sub 80/IrMn/Co/A1-oxide/Co/Fe(sub 20)Ni(sub 80) spin-valve-type tunnel junction were measured at the P and AP magnetization configurations of both ferromagnetic electrodes. The tendency of the tunneling magnetoresistance (TMR) ratio to decrease with the bias voltage agreed with the shape of the subtraction spectrum.

The shape of the dynamic conductance versus voltage of NiFe/AlO(sub x)/NiFe tunnel junctions is correlated with the intensity and duration of oxidation. Annealing of the junctions makes the tunnel barrier effectively thinner and taller, as implified by a fit to the parabolic conductance.

The spin-lattice relaxation rate in iron garnets containing ions of the rare-earth series features a peak in the temperature range from 30 to 100 K that is consistent throughout the group. Measurement data from high purity yttrium iron garnet also confirm that iron relaxation rates decrease monotonically with reducing temperatures, indicating that microwave magnetic loss at cryogenic temperatures can be reduced below room temperatures values if offending rare-earth impurities are removed.

A study was conducted to analyze the magnetic characteristics of CeF2 single crystals. Direct-current magnetization and linear and nonlinear alternating-current susceptibility measurements were carried out to perform the analysis. Experimental results indicated several anomalies below the Curie temperature that may be correlated to the development of antiferromagnetic spin fluctuations of growing spatial extension.

A study was conducted to analyze the spin dyanmics and energy gap of an iron dimer. The compound was prepared in the form of polycrystalline powders. The Metronique Ingegnerie Squid was utilized to carry out dc susceptibility measurements. Experimental results indicated that the origin of the nuclear relaxation in the cluster may be correlated on the broadening of the electronic levels.

Use of electron diffraction and high resolution transmission electron micrographs enable the characterization of granular Fe(x)Cu(sub 1 - x) films. These films show superparamagnetic relaxation and a reduction in the average magnetic moment up to 450 iron atoms. Weak exchange coupling between iron atoms causes spin excitations of long wavelength, which is confirmed by ferromagnetic resonance studies. Below 300 K, magnetization depends on temperature as given by Bloch's T3/2 law.

Simultaneous gamma, x-rays and conversion electron Mossbauer spectroscopic studies indicate the influence of temperature on the antiferromagnetic Fe3BO6 crystal. Heating the crystal gives rise to paramagnetic regions, which expand with increasing temperature. The whole surface turns paramagnetic at a particular temperature below Neel point. At Neel point the whole crystal becomes paramagnetic.

The replacement of Fe atoms with Mn atoms reduces the ferromagnetism of YFe2 due to decrease in exchange splitting, as shown by the fully self-consistent discrete variational method. Magnetization, Mossbauer measurements, diffuse neutron scattering and NMR studies indicate the ferromagnetic coupling between Fe and Mn atoms. The decrease in Fe moment is due to the hybridization between the 3d minority-spin bands of Fe and Mn.

Transmission electron microscopy helps analyze the microstructure of nanocomposite Fe80(SiO2)20 films with 150 to 5,000 angstrom thickness, obtained by rf magnetron sputtering, to assess the thickness dependence of the magnetic and electrical properties of these films. Thickness dependence of the crystallites extends to resistivity, stacking and connectivity. The magnetic properties depend on the microstructures that vary with film thickness. The magnetic coercivity of the films is also thickness-dependent.

Thermogravimetric analysis and Mossbauer spectroscopic studies of the magnetic properties of Nd3(Fe,Ti)29 compounds subject to interstitial modification with C, H and N reveal that H addition enhances Tc but not iron moment, while N addition enhances both Tc and iron moment. Lattice expansion values for the maximum levels of six hydrogen and four nitrogen atoms per formula unit range from 2% to 6.5%. Carbon addition is not feasible due to the decomposition of the materials during reactions with C.

Radio frequency diode sputtering onto polycrystalline Al2O3 substrates at 650 degrees C yields crystalline films of strontium hexaferrite. The films are prepared nonepitaxially. The severe Sr depletion occurring during sputtering is eliminated by using Sr enriched targets. The annealing of the films at 500 Torricelli of O2 increases film coercivity.

Doping of SrFe12O19 with 0.3 mol per unit of Ga3+ or In3+ ions causes a division in the 12K octahedral subspectrum. The splitting occurs due to a magnetic exchange interaction of some of the 12k2 Fe3+ ions. The random changes in the exchange interactions do not influence the 12k splitting.

Constitutive equations are used to measure of time dependence magnetization which reveals the basic characteristic of magnetization reversal processes. The activation volumes, associated with the magnetization reversal processes are, estimated by the application of a fluctuation field. The activation volumes are measured at room temperature and the systems are assumed to be isothermal.

The presence of three structures in compounds of the FeRhP system is confirmed by synthesis and analysis. The orthorhombic O10-NdCoB, hexagonal H3-Fe2P and hexagonal H12-FePdP are the three structures occurring in the FeRhP system. The structures are identical to polytypes caused by packing of the pseudorhombohedral FeRhP subcell. The three phases exhibit different magnetic properties.

A model, which was originally used to study R2Fe17 and R2Fe17N(x) compounds, was employed to evaluate the Mossbauer spectra of Sm2Fe17, Ho2Fe17 and their nitrides determined at various temperatures. The model correlated with crystallographic changes that occurred during nitrogenation, and with band structure calculation predictions. Crystallographic lattice expansion induced a sudden increase on the Curie temperature of the nitrides.

The preparation and magnetic behavior of a peculiar pentacoordinate Fe3+ compound, which was essential for scattering measurements and neutron diffraction, were studied. This compound exhibited magnetic anisotropy, which was analogous to the normal material, and critical behavior when ferromagnetic transition took place at 2.457 Kelvin.

A study of the magnetism and spin dynamics of nanoscale FeOOH particles, that were not based on either alpha-FeOOH or alpha-Fe2O3, revealed that the particles were transformed to Fe3O4 (alpha-Fe2O3) on heating in vacuum at 800 K. These superparamagnetic nanoscale particles, which were studied at various temperatures, revealed thermal motion.