Synthesis and analysis of samarium-iron-titanium sputtered films with intrinsic coercive force greater than 30 KOe.
Item
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Title
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Synthesis and analysis of samarium-iron-titanium sputtered films with intrinsic coercive force greater than 30 KOe.
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Identifier
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AAI9029950
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identifier
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9029950
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Creator
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Kamprath, Narayanan.
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Contributor
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Adviser: Fred J. Cadieu
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Date
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1990
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Language
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English
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Publisher
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City University of New York.
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Subject
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Physics, Condensed Matter | Physics, General
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Abstract
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Rare-earth transition metal film magnets of several new phases in the Sm-Fe-Ti system have been prepared by special sputtering methods. Film samples have been directly crystallized onto heated substrates as well as first deposited amorphous and then subsequently crystallized. Magnetic fields have been applied during the sputter deposition and during the crystallization to induce in-the-film-plane anisotropies into the growing films. For the Sm-Fe-Ti system, a hard magnetic phase has been observed in subsequently crystallized amorphous deposits. As a function of composition, the high {dollar}\rm \sb{lcub}i{rcub}H\sb{lcub}c{rcub}{dollar} Sm-Fe-Ti phase has been shown to exhibit a maximum room temperature intrinsic coercivity of 38.5 KOe at a nominal composition of {dollar}\rm Sm\sb{lcub}20{rcub}Fe\sb{lcub}70{rcub}Ti\sb{10}{dollar}. This high {dollar}\rm \sb{lcub}i{rcub}H\sb{lcub}c{rcub}{dollar} phase we report to be a SmCo{dollar}\sb5{dollar} related hexagonal structure with a nominal formula of Sm{dollar}\sb7{dollar}(Fe,Ti){dollar}\sb{lcub}30{rcub}{dollar}. For the high {dollar}\rm \sb{lcub}i{rcub}H\sb{lcub}c{rcub}{dollar} Sm-Fe-Ti films it has been possible to synthesize films that exhibit extreme in-the-film-plane anisotropy for fields of {dollar}\pm{dollar}20 KOe. Fields of {dollar}\pm{dollar}20 KOe applied in the film plane, but perpendicular to the H{dollar}\rm \sb{lcub}s{rcub}{dollar} direction were not sufficient to measurably magnetize the film in that direction. This corresponds to an effective energy of at least 10{dollar}\sp7{dollar} erg/cm{dollar}\sp3{dollar} for magnetizing the film in the film plane parallel versus perpendicular to the H{dollar}\rm \sb{lcub}s{rcub}{dollar} direction. In addition the magnetic properties of the high {dollar}\rm \sb{lcub}i{rcub}H\sb{lcub}c{rcub}{dollar} Sm-Fe-Ti system containing small amounts of Al, V, and Zr have been studied. Films that have been directly crystallized onto heated substrates have exhibited several crystal phases such as 2-17, 1-5 as a function of composition and temperature. The Sm-Fe-Ti system also exhibited a soft magnetic phase of the ThMn{dollar}\sb{12}{dollar}-type at a nominal composition of Sm(TiFe{dollar}\sb{11}{dollar}). A systematic experimental research has been conducted by varying the sputtering parameters such as substrate temperature, sputtering gas pressure, deposition rate, and the distance between the target and the substrate. A model is also presented based upon the crystallite grain sizes and magnetic alignment energy that correlates the differences in the degree of in-the-film-plane anisotropy induced in these systems.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
