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David I. Paul and Donald R. Sadoway. Sunter, Kristen A. (Kristen Ann), 1982- Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. Massachusetts Institute of Technology. Department of Materials Science and Engineering 2006-05-15T20:25:41Z 2006-05-15T20:25:41Z 2004 2004 http://hdl.handle.net/1721.1/32726 56513434 Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004. Includes bibliographical references (leaf 21, first group). The magnetic behavior of a material is governed by the variation in anisotropy direction from grain to grain as well as the changes in ferromagnetic parameters at grain boundaries and other defect regions. For example, transmission electron microscopy results show that chromium segregation occurs at the grand boundaries in CoCrTa films, which are used in hard disk drives. In this paper, we model the case of two adjacent semi-infinite grains with arbitrary crystalline orientations with respect to each other. A Gaussian distribution is used to model the change in magnetic properties at the interface, and boundary conditions are imposed on the direction of magnetization deep within the grains and at the interface. The effects due to the diffuse interface are included using perturbation theory. The sum of the exchange, anisotropy and Zeeman energies is minimized, and the resulting Euler equation is solved analytically. A profile of the magnetization orientation in an inhomogeneous medium in an applied field is obtained to show the extent of the effects of grain boundary segregation. These results can direct future large-scale computer calculations and media improvement. by Kristen A. Sunter. S.B. 22, [20] leaves 1987029 bytes 1985521 bytes application/pdf application/pdf eng Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Materials Science and Engineering. An analytic solution for magnetization distribution in multigrain ferromagnetic materials in an applied magnetic field Thesis application/pdf Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="92d8d2aa-77b6-4232-b68c-93950eaf2210"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>An analytic solution for magnetization distribution in multigrain ferromagnetic materials in an applied magnetic field</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2004</PublicationDate> <Authors> <Author> <DisplayName>Sunter, Kristen A. (Kristen Ann), 1982-</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Materials Science and Engineering.</Keyword> <Abstract>The magnetic behavior of a material is governed by the variation in anisotropy direction from grain to grain as well as the changes in ferromagnetic parameters at grain boundaries and other defect regions. For example, transmission electron microscopy results show that chromium segregation occurs at the grand boundaries in CoCrTa films, which are used in hard disk drives. In this paper, we model the case of two adjacent semi-infinite grains with arbitrary crystalline orientations with respect to each other. A Gaussian distribution is used to model the change in magnetic properties at the interface, and boundary conditions are imposed on the direction of magnetization deep within the grains and at the interface. The effects due to the diffuse interface are included using perturbation theory. The sum of the exchange, anisotropy and Zeeman energies is minimized, and the resulting Euler equation is solved analytically. A profile of the magnetization orientation in an inhomogeneous medium in an applied field is obtained to show the extent of the effects of grain boundary segregation. These results can direct future large-scale computer calculations and media improvement.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>