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The behavior of nanoscale infrared antenna elements depends upon the dynamic conductivity of thin metallic films. Spectroscopic ellipsometer measurements of noble metal films show that when the product of the incident radiation frequency and the relaxation time is greater than unity, anomalous dynamic electron transport effects occur. In this regime electron scattering increases the conductivity of alloyed metallic films as demonstrated by ellipsometry measurements of films from the Au-Cu system. A binary alloy thin film was fabricated with equal parts of Au and Cu, and the dynamic conductivity was measured to be 300% larger than the high frequency conductivity of pure Au or pure Cu films at wavelengths in the 3–5 μm band. When electronic scattering is reduced, ellipsometer measurements of Au and Cu films taken near 4 K demonstrate that the IR conductivity decreases to 20% of the value measured at 300 K at wavelengths in the 3–5 μm band. Using measured dc relaxation times, a model to explain deviations from Drude behavior was developed using the theory of the anomalous skin effect and frequency dependent relaxation time. This model was in quantitative agreement with the measured data. The ability to design an alloyed metallic thin film using a calculated ideal dc relaxation time to produce the greatest possible dynamic conductivity for infrared antennas and metamaterials was demonstrated. [ABSTRACT FROM AUTHOR]

Two series of epitaxial CoPt and FePt films, with nominal thicknesses of 42 or 50 nm, were prepared by sputtering onto single-crystal MgO(001) substrates in order to investigate the chemical ordering and the resultant magnetic properties as a function of alloy composition. In the first series, the film composition was kept constant, while the substrate temperature was increased from 144 to 704 °C. In the second series the substrate temperature was kept constant at 704 °C for CoPt and 620 °C for FePt, while the alloy stoichiometry was varied in the nominal range of 40–60-at. % Co(Fe). Film compositions and thicknesses were measured via Rutherford backscattering spectrometry. The lattice and long-range order parameter for the L10 phase were obtained for both sets of films using x-ray diffraction. The room-temperature magnetocrystalline anisotropy constants were determined for a subset of the films using torque magnetometry. The order parameter was found to increase with increasing temperature, with ordering occurring more readily in FePt when compared with CoPt. A perpendicular anisotropy developed in CoPt for substrate temperatures above 534 °C and in FePt above 321 °C. The structure and width of the magnetic domains in CoPt and FePt, as seen by magnetic force microscopy, also demonstrated an increase in magnetic anisotropy with increasing temperature. For the films deposited at the highest temperatures (704 °C for CoPt and 620 °C for FePt), the order parameter reached a maximum near the equiatomic composition, whereas the magnetocrystalline anisotropy increased as the concentration of Co or Fe was increased from below to slightly above the equiatomic composition. It is concluded that nonstoichiometric L10 CoPt and FePt, with a slight excess of Co or Fe, are preferable for applications requiring the highest anisotropies. [ABSTRACT FROM AUTHOR]

Magnetic media using materials with high uniaxial magneto-crystalline anisotropy, K[sub u], combined with a thermal assist to overcome write field limitations have been proposed as one of the potential technologies to extend the areal density of magnetic disk recording beyond the limitations of current technology. Here we present an investigation on structural and temperature dependent magnetic properties of chemically ordered epitaxial Fe[sub 55-x]Ni[sub x]Pt[sub 45] thin films. Increasing Ni additions result in a steady reduction of magneto-crystalline anisotropy, saturation magnetization, and Curie temperature. The ability to control thermomagnetic properties over a wide range makes Fe[sub 55-x]Ni[sub x]Pt[sub 45] and similar FePt-based pseudo-binary alloys attractive base materials for media applications in thermally assisted magnetic recording. [ABSTRACT FROM AUTHOR]

Analyzes phase formation kinetics in niobium/aluminum multilayered thin films. Details on the experiment; Results of the study; Conclusion.

Presents a study that investigated the phase formation sequence for the reaction of niobium and aluminum in multilayer thin films. Identification of the specific phase sequences; Analysis of the transmission electron micrograph of the phase formation; Evaluation of the x-ray diffraction pattern of the films.

Presents a study which examined the effect of an aluminum oxide layer at the interface of aluminum/niobium on phase formation in thin film binary diffusion couples. Experimental details; Results and discussion; Conclusion.

Focuses on a study on grain boundary diffusion and its effects on the magnetic properties of cobalt-copper and cobalt-chromium thin film bilayers. Information on x-ray photoelectron spectroscopy; Methodology; Results and discussion.

Present information on a study that examined the structural and chemical properties of barium-ferrite thin-film. Experimental procedure; Results and discussion on the study.

The loss of Fe due to oxidation or diffusion into the substrate can prevent the successful preparation of well-ordered, stoichiometric, FePt nanoparticles. In this work we report the composition changes during annealing observed for small (<10 nm) FePt nanoparticles on thermally grown SiO2 layers on Si wafer substrates. Additionally, we describe the use of a controlled reducing gas mixture, Ar+H2+H2O, to reduce the loss of Fe. [ABSTRACT FROM AUTHOR]

Multilayers of Ba0.5Sr0.5TiO3 (BSTO) and BaFe12O19 (BaM), with tunable permeability and permittivity are attractive systems for radio frequency and microwave applications. We have grown multilayers of BSTO and BaM using magnetron sputtering on Al2O3 substrates. Film growth conditions such as sputtering parameters were optimized to obtain high quality multilayers. X-ray diffraction established that both BSTO and BaM were formed and cross-sectional SEM studies showed sharp interfaces between BSTO and BaM layers. Magnetization showed a large coercivity (~2000 Oe) consistent with the hexaferrite component. The hysteresis loops also revealed the distinct influence of magnetocrystalline and shape anisotropies at different temperatures. [ABSTRACT FROM AUTHOR]

Presents information on a study that observed giant magnetoresistance of order at room temperature in annealed multilayers of Ni[sub80]Fe[sub20]/Ag prepared by magnetron sputtering. Experimental procedure; Results and discussion on the study.

Presents a study which discussed the measurement of the structural and magnetic depth profiles of annealed Ni[sub80]Fe[sub20] multilayers using X-ray and polarized neutron reflectivity. Aspect associated with the giant magnetoresistance; Consistency of the spin ordering; Importance of neutron scattering; Use of polarized neutron reflectivity.

Presents a study which investigated grain growth and ordering kinetics in a 10-nanometer-thick cobalt platinum alloy film. Coercivity of annealed films; Electron diffraction analysis of the as-deposited film; Analysis on the mechanisms of grain growth.

Explains the origin of giant magnetoresistance in a new sensor structure incorporating discontinuous multilayers of NiFe thin films separated by silver interlayers. Applications of giant magnetoresistance in multilayer systems; Components of the multilayer systems; Results of annealing the multilayers in the rapid thermal annealer.

Presents a study that prepared thin films of barium (Ba)-hexaferrite of the magnetoplumbite structure on different sapphire substrates of orientation. Properties of the epitaxial Ba-ferrite thin films prepared; Comparison of easy-axis orientations determined by torque magnetometry and crystallographic orientation; Anisotropy constants measured for the different orientations.

Studies the crystallographic structure of CoPtCr/CrV thin films as revealed by cross-section transmission electron microscopy and x-ray pole-figure analysis and discusses its relevance to magnetic properties. Characteristics of the crystallographic structure and coercive force of CoPtCr/CrV thin films; Degree of epitaxy between the CoPtCr and CrV sublayer; Coercivity of the films.

This letter describes materials and electrical characterization of Pt-Ru binary alloy metal gate electrodes for control of the electrode work function. The work function of the Pt-Ru binary alloy system can be tuned over a wide range of 4.8–5.2 eV. The results indicate that the change of film properties, i.e., resistivity, work function, and crystal structure, with composition is consistent with the equilibrium phase diagram and that the work function in the face-centered cubic and hexagonal close-packed single-phase regions is only weakly dependent on composition, whereas a strong dependence is observed in the intermediate compositional range. [ABSTRACT FROM AUTHOR]

The reaction between solid layers to form a product phase has been studied using scanning calorimetry of multilayer Nb/Al and Ni/amorphous-Si thin films. The most striking feature for both materials systems is the occurrence of two maxima in the reaction rate during the formation of a single product phase, suggesting a two step growth process. A model has been developed in which the first step is taken to be the nucleation and two-dimensional growth to coalescence of the product phase, in the plane of the initial interface. The second step is taken to be the thickening of the product layer by growth perpendicular to the interface plane. The success of this simple model in describing the principal features of the experimental results on two different materials systems suggests that nucleation is an important aspect of phase formation and selection in these thin-film reactions. [ABSTRACT FROM AUTHOR]