Asymmetric Magnetization Reversal in a Single Exchange-Biased Micro Bar

The asymmetric magnetization reversal is studied in a single exchange-biased microbar of 1.5 x 13 micrometer with anisotropic magnetoresistance and magnetic force microscopy. The particle has a moment of less than 10^-9 emu and is not accessible with standard magnetometry. The asymmetric hysteresis loop of CoFe/CrMnPt shows a repeatable rotation process, followed by an irreversible nucleation process that is marked by jumps in the magnetoresistance. The induced unidirectional anisotropy enhances the rotation process in one branch of the hysteresis loop, followed by a sped up nucleation process. Imprinted ferromagnetic domain patterns left behind by the antiferromagnet are observed after the nucleation process occurred but before complete saturation is reached.Comment: 4 pages, 5 figure

Guiding Students on Their Purposeful Journeys – A Service Approach

Most formal approaches to career exploration are self-focused. Illusions and pitfalls abound if a student is not careful. Come along on a road less traveled in helping students choose a major as a path to career or vocation. By helping link their talents, gifts and abilities to how they can best serve others or advance society, students discover purpose and meaning behind their choices. Techniques will be presented to facilitate a process that can help students more confidently take the leap of faith into their respective career paths

Noise properties of magnetic and nonmagnetic tunnel junctions

Park WK, Moodera JS, Taylor J, et al. Noise properties of magnetic and nonmagnetic tunnel junctions. In: Journal of Applied Physics. JOURNAL OF APPLIED PHYSICS. Vol 93. AMER INST PHYSICS; 2003: 7020-7022.Low-frequency voltage fluctuations in magnetic and nonmagnetic tunnel junctions have been investigated. Tunneling magnetoresistance ratio of junctions ranged from 8.6% to 50% at room temperature. The origin of voltage noise was observed to be nonmagnetic. It was found that the resistance fluctuations lead to 1/f noise at room temperature, whereas the white noise was dominant at 77 K. A phenomenological noise parameter, defined for the comparison of noise levels in different junctions, was shown to scale with the junction resistance-area product. This observation suggests that low values of resistance x area are required for a low noise operation as well as for the integration of magnetic tunnel junctions. (C) 2003 American Institute of Physics