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Ortiz, V.

Publications and source records attributed to Ortiz, V..

Robust perpendicular magnetic anisotropy in off-axis sputtered europium iron garnet (EuIG) thin films

In this study, the rare earth iron garnet (REIG), Eu 3 Fe 5 O 12 (EuIG) has emerged as a promising material for ferrimagnetic insulator based spintronics. Earlier studies have shown that perpendicular magnetic anisotropy (PMA) in EuIG and other REIGs can be achieved by magnetostriction and misfit strain at the film-substrate interface. Typically, the strain relaxes significantly with thickness, limiting the thickness of films that can be grown using this strategy. Here we show PMA that does not reduce substantially with thickness in epitaxial EuIG films grown by off-axis sputtering; The PMA remains robust in films > 100 nm thick. Epitaxially induced strain with minimal relaxation is confirmed using high resolution symmetric and asymmetric x-ray diffraction reciprocal space maps.

36 MATERIALS SCIENCE↗

High temperature superconducting infrared imaging satellite

A low earth orbiting platform for an infrared (IR) sensor payload is examined based on the requirements of a Naval Research Laboratory statement of work. The experiment payload is a 1.5-meter square by 0.5-meter high cubic structure equipped with the imaging system, radiators, and spacecraft mounting interface. The orbit is circular at 509 km (275 nmi) altitude and 70 deg. inclination. The spacecraft is three-axis stabilized with pointing accuracy of plus or minus 0.5 deg. in each axis. The experiment payload requires two 15-minute sensing periods over two contiguous orbit periods for 30 minutes of sensing time per day. The spacecraft design is presented for launch via a Delta 2 rocket. Subsystem designs include attitude control, propulsion, electric power, telemetry, tracking and command, thermal design, structure, and cost analysis.

Angus, B.↗