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Domain transition in mixed phase manganites Amlan Biswas, University of Florida, DMR 0804452.
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Domain transition in mixed phase manganitesAmlan Biswas, University of Florida, DMR 0804452 The ability to control the magnetism of a material at the nanometer scale is required for high density memory devices and is an exciting challenge in materials physics. We are investigating a family of materials called manganites (chemical formula: La0.27Pr0.40Ca0.33MnO3) which display a temperature dependent size evolution of magnetic regions from about 1 nanometer to 1 micrometer. Under uniaxial strain exerted by the film substrate, NdGaO3 (NGO), this manganite shows anisotropic magnetization (M) i.e. it is easier to align the magnet in one direction (called the easy axis) compared to other directions, which leads to a single domain to multidomain transition when the size of the magnetic regions exceeds a critical value. This temperature dependent effect can be used to understand and possibly circumvent the superparamagnetic limitation in nanomagnets. Magnetic field (H) applied parallel to magnetic easy axis. H applied perpendicular to magnetic easy axis. Fig. 1. (a) Anisotropic magnetization in a mixed phase manganite and (b) the same material shows isotropic electrical resistivity ().
Domain transition in mixed phase manganitesAmlan Biswas, University of Florida, DMR 0804452 We have encouraged the participation and successfully recruited female and minority physicists in our research group. (cf. notes). Supported partially by this grant, summer 2009 REU student Kristen Voigt presented her research work in our group at the 2010 APS March meeting. As the faculty adviser of the University of Florida, Society of Physics Students, the PI has organized several outreach activities in area schools including the 2010 high school regional competition for the DOE National Science Bowl (fig. 3). Fig. 2. Icon Mazzaccari (Physics Undergraduate student, University of Florida) working with a low temperature scanning tunneling microscope. Fig. 3. Winners of the North Central Florida Regional DOE Science Bowl organized by the Society of Physics Students.