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Show ZnO/LSMO Superlattice Structures for Ultra-low-field Magnetic-sensing Devices Paul Slusser and Ashutosh Tiwari Department of Materials Science and Engineering Due to the continuing miniaturization of magnetic data storage into the nanoscale regime a need for magnetic sensors capable of detecting extremely small magnetic fields has been realized. Our research has been focused upon developing and studying materials suitable for such sensors as spin valves and magnetic tunneling junctions. The materials studied in our project possess the property known as gigantic magneto resistance (GMR). GMR is a large change in a materials resistivity with the application of a magnetic field. This effect was first demonstrated in metal alloys that require extremely high vacuum syntheses and protection from the atmosphere. Currently, metallic systems are used in hard drive read heads. However, GMR has been shown to occur in metal oxide compositions that have no need for high vacuum synthesis. Additionally several of these metal oxide compositions show colossal magneto resistance (CMR) where the change in resistance is even larger than in GMR allowing even smaller magnetic fields to be detected. We have successfully synthesized several different oxide compositions with the chemical formula, La(1-x)A(x)MnO(3) where A is Sr, Ba, or Ca, which show GMR. We synthesized ceramic targets and thin films of these materials by a novel sol-gel method and Pulsed Laser Deposition (PLD) respectively. The structural and chemical properties of the ceramic targets have been characterized by Electron Microscopy and X-Ray Diffraction. Electrical properties have also been studied as a function of temperature and magnetic field with these materials showing both metallic and insulating like conductivity. Preliminary results also show that the resistivities of the samples are sensitive to magnetic fields. We have also fabricated a primitive spin valve using PLD to deposit a layered structure of La(.7)Sr(.3)MnO(3) |ZnO| La.7Sr.3MnO3. This research is supported with funding from The University of Utah, Seed Grant Award. Paul Slusser is supported with funding from The University of Utah, Undergraduate Research Opportunities Program. |