Molecular Self-Assembly of Multilayer Low-Loss Ferrite Thin Films and Devices

This Air Force SBIR program would develop multilayered low-loss ferrite thin film materials for use in high frequency power electronic DC-DC voltage converters for next-generation small and lightweight electronic systems. The emphasis of the Phase Iprogram is on the development of ferrite material synthesis methods capable of yielding ultrasoft superparamagnetic ferrite films with controlled high resistivities and low defect concentrations in order to avoid excess loss at high switching frequencies.NanoSonic proposes to use modified electrostatic self-assembly (ESA) methods that allow the incorporation of magnetic, nonmagnetic and other molecular precursors into precisely-dimensioned multilayered thin films. Recent research suggests the feasibilityof such methods for the synthesis of ultrasoft, low-loss ferrite films several millimeters in thickness, and the ability to adjust magnetic properties through control over precursor chemistries and intermolecular arrangement within the film. Thin filmgrowth, molecular orientation and morphology will be determined using spectroscopy, ellipsometry, and both force and electron microscopy. The resulting lumped electronic properties of a fabricated prototype thin film inductor will be measured usingvibrating sample magnetometry, four-point resistance probe, and high frequency network analyzer instrumentation. NanoSonic would work with both Virginia Tech and a major U.S. aerospace electronic systems company to analyze material performance.Low-losshigh-frequency thin film ferrite materials and devices have immediate and widespread military and commercial applications in power electronic DC-DC voltage converters for future small and lightweight electronic systems. At even higher frequencies, suchferrites have uses in aircraft and space-based antenna systems and microwave engineering devices, including isolators, rotators, circulators, phase shifters, mixers and parametric amplifiers.