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A technology for microelectromechanical systems (MEMS) and microstructure fabrication is introduced where the bulk metallic glass (BMG) is formed at a temperature where the BMG exist as a viscous liquid under an applied pressure into a mold. This thermoplastic forming is carried out under comparable forming pressure and temperatures that are used for plastics. The range of possible sizes in all three dimensions of this technology allows the replication of high strength features ranging from about 30 nm to centimeters with aspect ratios of 20 to 1, which are homogeneous and isotropic and free of stresses and porosity. Our processing method includes a hot-cutting technique that enables a clean planar separation of the parts from the BMG reservoir. It also allows to net-shape three-dimensional parts on the micron scale. The technology can be implemented into conventional MEMS fabrication processes. The properties of BMG as well as the thermoplastic formability enable new applications and performance improvements of existing MEMS devices and nanostructures. [2006-0102] Index Terms--Amorphous materials, bulk metallic glass, materials processing, microelectromechanical devices, nanoteclmology, thermoplastic processing.

Thermally Stimulated Depolarization Current (TSDC) signals measured in polymers at the glass transition [T.sub.g] often exhibit intricate shapes that much depend on the thermal history and on the non-stationary condition used during experiments. This peculiar behavior is frequently explained in terms of a physical singularity of the molecular motions. We show that this singularity, i.e. unexpected values for activation energy and pre-exponential factor, obtained around [T.sub.g], result from the misuse of the Arrhenius law for treating the experimental data obtained in non-stationary experimental conditions. A simple model using time dependent configurational entropy for the material evolution and using a single Debye relaxation for the dielectric relaxation process is therefore proposed to explain the experimental behavior. The influence of the heating rate and of a non-Debye relaxation on the TSDC signal is also studied and clearly shows that the peculiar behavior of TSDC peaks can originate from the conjugated effects of entropy relaxation and non-Debye response. Index Terms--Thermally stimulated current, polymers, glasses, relaxation processes, glass transition.

The glass softening endotherm is interrupted by the crystallization exotherm, in the differential scanning calorimetry (DSC) scans of the annealed states of vapor-deposited, hyperquenched, and crystal-amorphized solids. The studies of hyperquenched kinetically frozen states of high fictive temperature of proteins would be valuable in investigating various stages of protein transitions.

The film properties of hydrogenated amorphous silicon (a-Si:H) prepared by glow-discharged (GD) decomposition of silane under visible-light illumination is reported. The defect density depends exponentially on the intensity of incident visible light.

The study of the residual stresses in Fe40Ni40(Si + B)19Mo1 and Fe40Ni38B18Mo4 amorphous ribbons is discussed. The coercivity increases linearly with the increase in stress applied on the region above 80 MPa for Fe40Ni40(Si + B)19Mo1 and 50 MPa for Fe40Ni38B18Mo4.

Several mechanical experiments are conducted to explain the tensile fracture morphologies exhibited by the bulk metallic glasses (BMGs). The tensile fracture of the BMGs is shown to be highly affected by the damage mechanisms that are associated with thermal softening and weakening.

Several analyses are conducted to explain the different thermodynamic functions exhibited by the bulk metallic glass forming different liquids and alloys. The configuration entropy of the system is shown to be highly dependent on the temperature.

Microalloying with 1 at. % zirconium has increased the critical size for Gd-based bulk metallic glasses (BMGs) and the enhancement of glass-forming ability has originated from the increase in the packing efficiency and high compound forming tendency between Zr and major constituent elements. Heat capacity data has shown that the broad magnetic transition emerging from topological disorder is responsible for the high relative cooling power (RCP) of Gd-based amorphous magnetocaloric materials.

The origin and consequences of abnormal behavior of supercooled liquid region (SCLR) in various bulk-forming metallic glasses (BMGs) are discussed. The abnormal behavior of SCLR is modulated by controlling cooling rate as well as by tailoring alloy composition, with the consequence that the modulated local heterogeneity in these BMGs have led to enhanced flexibility of the BMGs.

The relationship between the crystallization temperature and the heating rates for many metallic glasses, mainly rare earth-based and Zr-based metallic glasses, is examined. The Vogel-Fulcher-Tammann (VFT) equation is shown to be a better model for describing the heating rate dependence of the crystallization temperature for the metallic glasses.

Several studies are conducted for understanding and interpreting the thermal anomalies observed in the ternary [Ge.sub.42-x][Pb.sub.x][Se.sub.58] glasses near the charge carrier reversal threshold. The mechanisms involved in the carrier type reversal (CTR) taking place in these systems are also explained.

The shear deformation generated temperature rise in metallic glasses is estimated in a macroscopic three-dimensional axial symmetric thermoplastic model. The small sample thickness and/or high deformation rate has enabled the temperature to exceed the glass transition in the entire sample, which has produced a transition of the deformation mode from inhomogeneous to homogeneous viscous flow.

High-resolution x-ray photoelectron spectroscopy (XPS) is utilized to determine the structure of binary [Ge.sub.x][Se.sub.100-x] chalcogenide glass family (0

The power supply efficiency can be improved by using the glassy metal alloy [Fe.sub.77][P.sub.7][B.sub.13][Nb.sub.3] powder in an inductor core. The heat generation in the core is suppressed by using the low loss power and it has become easy to design a temperature rise in the entire power supply circuit.

The electrical relaxation in Cd[I.sub.2]-[Ag.sub.2]O-[V.sub.2][O.sub.5] superionic glasses are studied in wide frequency and temperature range. The conductivity relaxation time has shown Arrhenius behavior with an activation energy, which is almost equal to that of the dc conductivity, indicating that the same ions take part in the dc and the dc conduction.

A study was conducted to gain insight into an individual alloy system for marginal metallic glasses (MGs), the fragility of supercooled liquids (m) which is inversely proportional to the fragility of superheated melts (M) that depends on the differently inherent characteristics temperatures. The increased stability of the superheated melt lead to more fragile supercooled liquid which results in formation of alloy system with better glass-forming ability (GFA).

Ab initio molecular dynamics simulation is used for studying the structures of [Fe.sub.78][M.sub.9][B.sub.13] (M=Nb, Si, and Zr) melts. The structural and dynamical properties of these melts have changed with different M elements and the degree of complexity of molten structure caused by the interactions among Fe, M and B has played a vital role in their glass forming ability.

The effect of metalloids composition in Fe-Pt-metalloids alloys on the glass-forming ability is explored to develop [Fe.sub.55][Pt.sub.25][Si.sub.16][B.sub.2][P.sub.2], [Fe.sub.55][Pt.sub.25][Si.sub.15][B.sub.3][P.sub.2] and [([Fe.sub.0.55][Pt.sub.0.25][Si.sub.0.16][B.sub.0.02][P.sub.0.02]).sub.96][Zr.sub.4] (at%) glassy alloys with [DELTA][T.sub.x] of 37 K and 48 K, respectively. These Fe-Pt-based glassy alloys are found to have great potential for fabrication of hard magnetic micro/nano structures due to their high magnetocrystalline anisotropy of the [L1.sub.0] phase.

The low-temperature specific heat (low-T [C.sub.p]) and other properties of a series of representative bulk metallic glasses (BMGs) are analyzed. The results have shown that not only the peak of the glass transition in the differential scanning calorimetry (DSC) curves is affected by the thermal treatments, the peak in low-T [C.sub.p] is also affected by the annealing and quenching processes and the magnitude of the boson peak (BP) has decreased after annealing and quenching at lower cooling rates.

Melt-spinning in the form of ribbons is used to prepare and study the magnetic properties of the [Nd.sub.49][Al.sub.13][Ni.sub.38] amorphous alloy. The findings from the hysteresis and temperature-dependent magnetization measurements provide insight into occurrence of a reentrant spin-glass behavior on cooling.

H diffusion constants are determined from steady-state fluxes through Pd-Ag alloy membranes. The activation energies for diffusion are determined as a function of H content in the dilute range for many Pd-Ag alloy membranes.

A novel method of detecting the glass -> liquid transition at high pressures which comprises measuring the relative volume change incurred upon heating glassy samples into the liquid state is reported.

The magnetocaloric effect of Mn-containing Hitperm type alloys ([Fe.sub.60-x][Mn.sub.x][Co.sub.18][Nb.sub.6][B.sub.16] (x = 0, 2, 4)) is analyzed. It is shown that the Mn addition has not only decreased the Curie temperature of the amorphous alloys to temperature closer to room temperature, but also the peak entropy change and the refrigerant capacity of the material.

The magnetocaloric effect of FeMoCuB amorphous alloys is analyzed. The analysis has shown that controlling the Fe/B ratio in soft magnetic FeMoCuB amorphous alloys with low B content has helped in tuning the temperature at which the maximum magnetocaloric effect takes place, without changing the magnitude of the magnetic entropy change.

New parameters are described for glass forming ability (GFA) as it is important for designing and developing new bulk metallic glasses (BMGs). The modified [gamma] parameter has shown very good correlation with the GFA of bulk metallic glasses.

A study on the effect of Co addition on the magnetocaloric effect of amorphous alloys with Nanoperm-type composition is conducted for temperatures above room temperature. Co addition produces an increase in the maximum magnetic entropy change and a shift of its associated temperature to higher temperatures.

A Ti-based metallic glass matrix composite with 10 vol % TiC is synthesized by mechanical alloying and the thermal stability and crystallization kinetics of the metallic glass and composite powders are investigated by differential scanning calorimetry in the mode of isochronal heating and isothermal annealing. The addition of 10 vol % TiC particles into a Ti-based metallic glass matrix might slightly affect the crystallization kinetics of the glassy matrix.

The observation of fast light-activated relaxation in a Ge-Se glass illuminated with subband gap light from a Ti-sapphire laser is reported. Irradiation of the Ge-Se glass appears to saturate and reach a state of dynamic equilibrium between photoexcitation and relaxation.

An analysis of the glass-forming ability (GFA) of amorphous [Fe.sub.67][Co.sub.9.5][Nd.sub.3][Dy.sub.0.5][B.sub.20] is performed in terms of the width of the supercooled liquid region, the reduced glass transition temperature, the recently proposed parameter gamma, the Hruby parameter [K.sub.gl], and the stability parameter S. The value of the parameters obtained predict that the alloy has a good GFA, which can be cast in bulk form, whereas in reality the success of casting fully glassy specimen is limited to only 0.5 mm diameter rods.

A survey of the elastic, mechanical, fragility and thermodynamic properties of bulk metallic glasses (BMGs) and glass-forming liquids is described. Results show good correlations between elastic constants of BMGs and the glass transition temperature, melting temperature, mechanical properties and liquid fragility, which have helped in the development of a series of rare-earth-based BMGs with desirable properties.

The relationship between spatially heterogeneous dynamics (SHD) and jamming is studied in a glass-forming binary Lennard-Jones system via molecular dynamics simulations. It is found that force chains constructed based on the magnitude of pairwise positive instantaneous forces are composed of both localized and mobile particles, therefore there is no one-to-one correspondence between force chains and locally mobile or immobile regions of the liquid.

Molecular simulations and an inherent structure analysis are used to investigate the way in which the response of a glass to stress depends on its thermal history. The results show that as glasses are strained, more highly annealed glasses remain in their initial metabasin up to larger strains.

The multidimensional potential-energy 'landscape' formalism offers useful insights into the properties of supercooled liquids and glasses. However, its mathematical fundamentals present formidable subtlety and complexity. The logarithmic modification has the effect of eliminating the positive-temperature ideal glass transition of the precursor pure-Gaussian model.

The results of measurement of the thermal properties -thermal diffusivity, effusivity, conductivity and heat capacity on four glass systems that are known to undergo carrier-type reversal (CTR) at specific metal concentrations are reported. It is found that all the thermal properties show anomalous variations at the metal concentrations at which CTR occurs.

Investigations on measurements of the coercive field and the magnetization work of nanocrystalline Fe(sub 73.5)Cu(sub 1)Nb(sub 3)Si(sub 13.5)B(sub 9) alloy are reported. Nanocrystalline samples are prepared from an amorphous precursor by Joule heating in the presence of tensile stress of 420 MPa.