The effects of short range order on the structural and transport properties of the $ rm Cu sb{1-x}Ni sb{x}Zr sb2$ amorphous metallic alloy system are studied. Depending on composition, these amorphous alloys crystallize into different structures. CuZr$ sb2$ has the I4/mmm (C11) structure and NiZr$ sb2$ has the I4/mcm (C16) structure. It is believed that the short range order in the amorphous phase is related to the final crystalline phase. A careful study (using differential scanning calorimetry, X-ray diffraction on as made and crystallized states, room temperature magnetic susceptibility and resistivity, and a determination of the superconducting transition temperature of as-made and annealed states) has been done to see what transport properties are affected. / It is observed that there is a linear increase in the values of the susceptibility, resistivity, and superconducting transition temperature of the system from CuZr$ sb2$ to NiZr$ sb2.$ This is attributed to an increase of the electronic density of states as the concentration of Ni increases. There is little or no influence on transport properties due to topological short range order.

Electrochemical methods have been used to measure the solubility and diffusivity of hydrogen in amorphous $Ni sb{60}Zr sb{40}$ over a wide range of hydrogen concentrations. It is found that Sievert's law is not obeyed and that the concentration of hydrogen in the metallic glass varies as $P sp{1/4}$, P being the pressure of hydrogen. In the concentration range of hydrogen measured, the diffusion constant of hydrogen increases by more than a factor of ten. A Gaussian distribution of hydrogen binding energy was used to explain the concentration dependence of chemical potential. A possible explanation to the concentration dependence of diffusion coefficient was also given.

We have used a new type of torque magnetometer: a piezoresistive cantilever. It detects the force and torque applied to the end of the cantilever beam by changes in its resistance. We report the first use of this device at temperatures below 1 K. We observed a hysteretic behavior of the resistance at low magnetic field (less than 10 mT) in that temperature range. At higher field it has a smoothly varying magnetoresistance which permitted us to measure the de Haas-van Alphen (dHvA) effect in two superconductors: $ kappa$-(BEDT-TTF)$ sb2$Cu(NCS)$ sb2$ and Sr$ sb2$RuO$ sb4.$ These measurements demonstrated that a large excitation current can be used if the sample is well thermalized but that torque interactions (TI) can affect the signal. TI can be reduced by the use of feedback. We also present measurements above 75 K of $H sb{c1}$ of YBa$ sb2$Cu$ sb3$O$ sb{6.9}$ obtained by modulating the field and measuring the torque signal at an harmonic of the modulation frequency.

Spin fluctuations (SF) are magnetization fluctuations in a metal. They have been proposed as the fundamental origins of the finite temperature properties of transition metals. This thesis presents amorphous iron-zirconium ($a$-Fe$ sb{x}$Zr$ sb{100-x}$) as an ideal system in which to study SF. $a$-Fe$ sb{x}$Zr$ sb{100-x}$ transforms from an exchange-enhanced paramagnet to a weak ferromagnet with increasing $x$, while the atomic structure remains virtually unchanged. The enhancement by SF of the effective electron mass has been studied in $a$-Fe$ sb{x}$Zr$ sb{100-x}$ by low temperature calorimetry. We report the first observation of the complete quenching or suppression of SF in a metal, achievable by either raising the temperature, or by applying a high magnetic field. This complete quenching allows us to rule out the formation of super-paramagnetic clusters, the only other plausible explanation of the data. $a$-Fe$ sb{x}$Zr$ sb{100-x}$, therefore, shows the clearest evidence to date of SF in the electronic properties.

Soft magnetic $ rm Ni sb{ it x}Co sb{ it 100-x}$/Cu multilayers in the range x = 20 to 80 have been prepared by DC-magnetron sputtering. NiCo alloys were chosen because of their small magnetoelastic parameters around the range x = 70-80 and very small lattice mismatch between NiCo and Cu. This combination of parameters should lead to good giant magnetoresistance (GMR) with a small saturation field. Structural characterization reveals that high quality layered structures were obtained. Quantitative interpretation of the superlattice structure parameters, such as interface roughness, interfacial mixing profiles and layer-thickness disorders, have been carried out by modelling the X-ray diffraction data. / GMR was found to be largest at x = 80 with well-defined oscillations as a function of the thickness of the Cu layer, mirroring the interlayer magnetic coupling. In particular, GMR with small saturation fields around Cu thickness near the second MR maximum (t$ sb{Cu}$ = 20A) will be technologically important because of the very high magnetic field sensitivity. Correlating the multilayer structure to the GMR allow us to optimize the structural parameters by enhancing the spin-dependent interfacial scattering in a high quality layered structure. Direct observation of the simple antiferromagnetic order has been achieved by the presence of the (0,0,${1 over2})$ wavevector in small angle neutron scattering experiments. A near-perfect antiferromagnetic spin arrangement is found for a Cu thickness t$ sb{Cu}$ = 20 A, that can be readily aligned ferromagnetically in a small external field of less than 200 Oe. / A complementary system, FM/Ag (FM = $ rm Ni sb{81}Fe sb{19}, Ni sb{80}Co sb{20}$ and $ rm Ni sb{66}Co sb{18}Fe sb{16})$ granular multilayer prepared by annealing multilayers, has also been studied. Enhanced magnetoresistance observed in these systems is shown to be controlled by the size, concentration and thermal stability of the magnetic precipitates in a nonmagnetic matrix. For a particular multilayer structure with a magnetic layer of 20 A, annealed at around 325$ sp circ$C, a GMR of $ sim$4% with a characteristic saturation field of 10 Oe was found, leading to a high magnetoresistive sensitivity of $ sim$0.4%/Oe at room temperature.

This exploratory study examined the predictive ability of perceived work environment characteristics on employees' level of motivation to learn and growth need strength. It looked at motivation to learn within the context of two types of training: formal training and on-the-job training. It also examined the existence of group differences in motivation and in perceptions of the work environment. The sample was 117 middle management staff at a Canadian research university, varying in age, level of education, job classification, work unit, and job and institutional tenure. Data was collected using a questionnaire consisting of scales from the management and educational literature. Using multiple regression analysis and MANOVAs, workplace environmental characteristics were found to be predictors of employee motivation. The best predictor of motivation to learn was a composite measure of incentives, while the best predictor of growth need strength was a composite measure of lack of independence and freedom of choice. No group differences in motivational characteristics were found, however, there were differences in perceptions of the work environment.

We investigate the phenomenon of phase organization in charge density waves. Coppersmith and Littlewood [87] have argued that charge density waves become organized into a "minimally stable" state when subject to a pulsed driving force. They have also proposed that the pulse duration memory effect, observed by Fleming and Schneemeyer [86], is evidence for this self organizing behaviour. / We review the microscopic origins of charge density waves, experimental results, and theoretical models of charge density waves. We also review theories of complex systems, and, in particular, the phase organization theory proposed by Tang et al. [87]. We focus on how the phase organization theory applies to the dynamics of charge density waves. / We investigate phase organization in a model of elastically coupled particles subject to a periodic potential and a pulsed driving force. By numerical simulation of the model, we show that the phase organization behaviour is contingent on the existence of a large number of inequivalent metastable configurations in the model. We also show that this model is equivalent to a purely elastic model of charge density waves interacting with impurities. / We further investigate phase organization in a model of charge density waves that has been proposed by Karttunen et al. [99], in which the dynamical generation of phase slips is naturally accounted for. Based on the results of numerical simulations, we argue that phase slips reduce or eliminate the phase organization behaviour of charge density waves by breaking the elasticity of the system.

This thesis concentrates on Magnetic Dissipation Force Microscopy---instrumentation, experiments and theory of the origin of magnetic dissipation. / A home-built vacuum magnetic force microscope (MFM) was debugged. The electronic noise in the system was reduced to below the thermal cantilever noise and the microscope now operates at its theoretical maximum (thermally limited) sensitivity. Then, a new technique, magnetic dissipation imaging, was developed. It allows the imaging of variations of 10-17 W in dissipation with sub-100 nm resolution. A normal MFM image and a magnetic dissipation image can be acquired simultaneously on the same area of a sample. / A theory was developed which correlates the dissipation with micromagnetic structures in domain walls. We consider the energy dissipation through coherent generation of phonons via magnetostriction induced by domain wall width oscillations. A quantitative agreement of theory with experiments for a 110 nm thick Co/Ni multi-layer and a 4 nm thick Co film samples was obtained. This theory predicts two new phenomena: a minimum drive force needed to cause wall width oscillations and wall width resonances. / With the above mentioned microscope, magnetic domain structure, micromagnetic domain wall structure and the associated dissipation have been studied on several samples, including a 30 nm thick Ni80Fe20 patterned into 20 mum squares and a CoPtCr recording medium. The dissipation results show strong correlations with magnetic domain structure. In the Ni80 Fe20 sample, the dissipation signal shows pronounced maxima correlated with the domain wall positions. We suggest magnetoelastic losses and eddy current losses due to wall jumps are the origins of the dissipation. With an in-situ magnetizing stage, we also studied magnetization reversal processes and dissipation hysteresis in the Ni80Fe20 sample. Besides the nucleation and growth of reverse domains, the formation of a 360º wall was observed. The CoPtCr sample shows different dissipation properties with both larger and smaller than average dissipation value observed in the transition regions.

High energy ball milling of the Fe-Ti system is carried out over a wide range of compositions. Milling Fe$ rm sb{50}Ti sb{50}$ and Fe$ rm sb{40}Ti sb{60}$ produces a composite material with amorphous regions and nanometer-sized crystals. Milling Fe$ rm sb{67}Ti sb{33}$ leads to a single-phase amorphous alloy which absorbs hydrogen, in sharp contrast to the intermetallic compound of the same composition. The nanocrystalline samples on their part exhibit a narrowing of the miscibility gap and a reduction of the pressure of the absorption plateau. The change in absorption properties, which is due to the interaction between the nanocystals and the amorphous phase, is analyzed using a simplified model of the elastic stress. Finally, hydrogen is absorbed much faster by nanocrystalline alloys than by conventional materials.

In this dissertation, we review the physics associated with surfaces and interfaces in equilibrium and non-equilibrium. Our emphasis will be on interfaces that are driven far away from equilibrium with special interest in the phenomenon of kinetic roughening. Models which describe non-equilibrium interfaces will be introduced and analyzed using techniques such as the Renormalization Group, Monte Carlo simulations, and direct integration of the equation of motion. Different interface relaxation mechanisms will be discussed with a focus on surface diffusion, which is believed to be the dominant effect in Molecular Beam Epitaxy. These interface growth models generate self-affine structures with various correlations satisfying a dynamic scaling law. We compute the scaling exponents and functions. Finally, we study the effect of quenched impurities on the dynamics of a driven interface with a conservation law. The impurity effect leads to anomalous scaling exponents and qualitatively changes the interface dynamics. Our results are summarized in two articles to be published: Refs. (Govind and Guo, 1992; Govind, Guo and Grant, 1992).