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In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better utilization of the target material (around 80% to 90%) by eliminating the race track at the target as in conventional plasma magnetron sputtering systems. The potential and capabilities of this novel plasma sputtering device are demonstrated in this paper by the deposition of a number of different Cr thin films suitable for underlayers in thin-film media and for which we have performed a systematic X-ray and TEM analysis to determine the grain-size histograms, mean grain diameters, and their relationship to the sputtering processes. Index Terms--Cr thin films, grain-size control, novel plasma sputtering.

Sophomore physics majors in waves and optics can utilize a phasor model to observe multiple-slit interference patterns. The mechanical phasor model allows students to experience its qualitative and quantitative application first hand. The phasor is a helpful visual aid to augment standard algebraic analysis.

The dc circuit concepts of multiloop configuration, RC time constants and switches can be taught in the physics class through a hands-on exploration of a Playskool child's flashlight. The flashlight has an energy-saving feature that requires the main switch to be on and a switch in the handle to be depressed for the light to function. Students explore different circuit configurations to find the one causing the dimming of the bulb once the handle switch is released. The experiment gives students a real-world application for physics and experience with the uncertainty of real physics.

Magnetic/piezoelectric multiferroic heterostructures with a magnetic thin film on a piezoelectric slab provides a great opportunity to achieve a strong converse magnetoelectric coupling with great potential for voltage tunable magnetic devices. Efforts have been made in developing highly magnetostrictive RF magnetic materials with low magnetization using magnetic/piezoelectric heterostructures to generate large electric-field induced effective magnetic fields. In this work, we report on NiCr films having low magnetization and relatively large magnetostriction. Strong converse magnetoelectric coupling and large electric field tunable ferromagnetic resonance (FMR) bandwidths are achieved in layered NiCr/lead zirconate titanate (PZT) and NiCr/lead zinc niobate lead titanate (PZN-PT) multiferroic heterostructures. A large electric field induced effective magnetic field of 260 Oe for NiCr/PZT and 756 Oe for NiCr/PZN-PT was observed, corresponding to a giant magnetoelectric coupling coefficient of 13 Oe cm/kV in NiCr/PZT and 75.6 Oe cm/kV in NiCr/PZN-PT multiferroic heterostructures. A high voltage tunable FMR frequency range was observed, with fmax/fmin being 124 and 325% for NiCr/PZT and NiCr/PZN-PT. The strong converse magnetoelectric coupling of NiCr/PZT and NiCr/PZN-PT heterostructures provide great opportunities for electric field tunable RF magnetic devices. [ABSTRACT FROM AUTHOR]

Charge separation mediated by linearly-polarized light in transparent insulators is analyzed numerically by integrating the equations of motion of a bound charge. It is shown that large static and transient dipole moments can be induced by the magnetic component of light at nonrelativistic intensities regardless of whether the pumplight is coherent or incoherent. Quantitative estimates show that efficient conversion of optical beams to electrical power is possible in lossless dielectric media and that THz radiation can be generated in unbiased materials through the use of transverse optical magnetism. [ABSTRACT FROM AUTHOR]

Radiation transport and multiple scattering calculations are presented and compared with experimental observations to characterize light attenuation in high emissivity nanopowders irradiated with low power laser light at room temperature, and to explain the associated white light emission and the onset of melting. Using radiation tuned to an absorption resonance of Yb3+ dopants in Y2O3 nanopowder, we observed the onset of intense blackbody emission above a well-defined intensity threshold. Local melting of the compact above threshold leads to the formation of single crystal microtubes. Evidence is provided to show that two-flux transport theory and diffusion theory both significantly underestimate the absorption due to dependent, multiple scattering and that the threshold for the thermal runaway process responsible for this behavior is very sensitive to porosity of the random medium. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]