Broadband Conductive Atomic Force Microscopy for Studying Magneto-electronic Nanostructures

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Conductive atomic force microscopy is a versatile tool for measuring nanoscale variations in the electrical resistance. The goal of this research program is to extend its capabilities over a broad range of frequencies to study magneto-electronic devices. Computers and smart phones contain nanoscale storage and logic devices that operate at high speeds, and in a race for smaller, faster, and more energy efficient electronics, many novel magneto-electronic devices are being explored. The new conductive force microscopy tool will enable rapid testing of prototype devices at different stages of nanofabrication, which will assist in optimizing the processing conditions and speed up the development cycle. In addition, the relevancy of the technique will be for magnetic hyperthermia cancer treatment, which uses excitation in the 100 kHz - 1 MHz range, for magnetically controlled heating. The outcome of this research will be related to educational and outreach activities of training graduate and undergraduate students and by demonstrating the principles of scanning probe microscopy through undergraduate research projects and the IEEE Magnetics Society.The proposed research program will extend conductive atomic force microscopy to investigate thermal noise and magnetization dynamics in a spintronic devices at broad range of frequencies and by validating it operation through measurements on nanoparticles and nanodisks. Several kinds of magnetic nanostructures will be studied in order to test the operation of the high frequency scanning probe, and to gain new knoweldge at the nanosclae level. Crystallographically oriented nanoparticles will be patterned lithographically for investigation of the size-dependence of thermal fluctuations leading to superparamagnetic behavior, and isolated particles behavior applied to patterned nanoparticle assemblies with significant magnetostatic interactions. Patterned magnetic vortex structures will be investigated near their resonant frequencies (100-500 MHz). In the GHz range, the focus will be on ferromagnetic resonance of the oriented nanoparticles.