Neutron scattering studies of industry-relevant materials: connecting microscopic behavior to applied properties

Certain systems of oxides, nitrides and carbides have been recognized as the basic components of advanced materials for applications as engineering and electronic ceramics, catalysts, sensors, etc. under extreme environments. An understanding of the basic atomic and electronic properties of these systems will benefit enormously the industrial development, of new materials featuring tailored properties. We present an overview of neutron-scattering studies of the crystal phases, microstructure, phonon and magnetic excitations of key materials including rare-earth phosphates, phosphate glasses, nanostructured metal oxides, as well as silicon nitride and silicon carbide ceramics. A close collaboration among neutron-scattering experimentation, molecular-dynamics simulation and material synthesis is emphasized

Compact accelerator-driven neutron sources

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Crystal phases, microstructure and surface chemistry of industry-relevant nanostructured metal oxides.

Industries response keenly to two factors: the costs of materials and processing, and regulatory forces imposed by governments. The method of neutron scattering maybe applied to address these concerns. Slow (cold to epithermal) neutrons probe the organization and dynamic response of atomic nuclei and electrons in a substance thereby providing valuable knowledge toward the development of cost-effective means for materials preparation and possessing. Neutron facilities for basic research are funded by governments, thus these organizations are obliged to provide technical support to industries for the fulfillment of governmental policies. I hope to argue, based on these premises, the mutual beneficialness of a close collaboration between the industrial-research and neutron-scattering communities. In order to limit the scope of discussion, I shall illustrate the potential applications of neutron scattering for industrial problems by some recent studies of nanostructured metal-oxide catalysts

Inelastic neutron scattering from zircon

A lattice dynamical investigation of zircon (ZrSiO{sub 4}) has been carried out to obtain a microscopic understanding of its thermodynamic properties, as well as to examine possible soft modes that may contribute to the phase transformation to scheelite type under high pressure. We have measured the neutron weighted phonon density of states of zircon from a polycrystalline sample. The neutron spectra reveal one-phonon excitations extending to 1130 cm{sup -1}, with phonon bands centered at 226, 298, 363, 540, 661, 726, 945, and 1081 cm{sup -1}. A quantitative analysis of the neutron results was carried out using a lattice dynamical rigid-ion model. 4 refs., 3 figs

Control Management and Business Performances: the Malaysian Family SMEs Perspectives

This study examined the relationship between control management and family business performance in the Malaysian context. It has two objectives, the first being to determine the relationship of organizational credit control policy and procedures, employee development and motivation, and intelligence collection systems to subsequent collection reports in Malaysian family SMEs. The second objective is to investigate the moderating effect of participation in decision-making and work effort towards innovation and business performance. This is a descriptive study involving 90 senior executives employed in 90 Malaysian family SMEs/firms. A correlation analysis from this study confirmed previous researchers’ observations that high-level organizational commitment to credit control management is linked to improvements in business performance. The results suggest that three components – credit policy, employee development, and intelligence collection systems – are the most important predictors for the efficiency and effectiveness of credit control management.   &nbsp

Research opportunities with compact accelerator-driven neutron sources

Since the discovery of the neutron in 1934 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator–driven neutron sources (CANS) are becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target-moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS

Magnetic Ground State of Pr0.89_{0.89}LaCe0.11_{0.11}CuO4+α−δ_{4+\alpha-\delta} with Varied Oxygen Depletion Probed by Muon Spin Relaxation

The magnetic ground state of an electron-doped cuprate superconductor Pr$_{1-x}$LaCe$_x$CuO$_{4+\alpha-\delta}$ ($x=0.11, \alpha\simeq0.04$) has been studied by means of muon spin rotation/relaxation (\msr) over a wide variety of oxygen depletion, $0.03\le\delta\le0.12$. Appearance of weak random magnetism over entire crystal volume has been revealed by a slow exponential relaxation. The absence of $\delta$-dependence for the random magnetism and the multiplet pattern of muon Knight shift at higher fields strongly suggest that the random moments are associated with excited Pr$^{3+}$ ions under crystal electric field.Comment: 6 pages, 4 figures, submitted to J. Phys. Soc. Jp

A laser spectroscopic study of Nd-doped Zirconia

High-surface-area rare-earth (RE) modified zirconia powders prepared by solution methods can be used as catalytic support of noble metals and as electrolyte oxygen sensors in automobile exhaust-emission- control systems. Previous neutron-scattering study showed that substituting Zr with trivalent RE ions not only stabilizes the cubic and tetrgonal phases over a wide range of temperatures but also creates oxygen vacancies in the RE-Zr oxide solid solution. This work focuses on Nd fluorescence in Nd{sub 0.1}Zr{sub 0.9}O{sub 1.95} powders under laser excitation of the Nd{sup 3+} ground state to the {sup 4}G{sub 7.2} states. Distinct features were found at 8K in the {sup 4}I{sub 9/2}{r_arrow}{sup 4}G{sub 7/2} excitation and {sup 4}F{sub 3.2}{r_arrow}{sup 4}I{sub 9/2} emission spectra using two sets of incident and emission frequencies, respectively. Results are discussed in terms of site-sensitive local structures surrounding the Nd ions in the two-phased oxide structure