Influence of ultra-thin Au interface layers on the structure and magnetic anisotropy of Co films

Persistent Link:
http://hdl.handle.net/10150/282634
Title:
Influence of ultra-thin Au interface layers on the structure and magnetic anisotropy of Co films
Author:
Eickmann, James Thomas, 1970-
Issue Date:
1998
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
I have investigated the influence of an ultra-thin Au interface layer on the magnetic anisotropy of Co-Pd and Co-Cu structures. Sandwich structures of the form X/Co/Y/Cu/Si(111), with (X, Y) = (Pd, Pd), (Au, Pd), (Pd, Au), (Cu, Cu), (Au, Cu), and (Cu, Au) were studied. For each structure, a Au layer of systematically varied thickness (t(Au)) was inserted at one Co interface. I also investigated Co/Pd and Co/Cu multilayer systems. For each Co-Pd sandwich structures a maximum is observed in the magnetic anisotropy for t(Au) = 1 to 1.5 atomic monolayer (ML). For the Co/Pd multilayer system, a maximum in coercivity occurs with tAu = 0.5 ML. For each Co-Cu sandwich structure except (X, Y) = (Cu, Au), a minimum in magnetic anisotropy is observed at t(Au) = 1 ML. For the Co/Cu multilayer system, a decrease in magnetoresistance was seen with increased tAu except in multilayers with a relatively thin Co layer thickness (∼3 ML) which display a peak in magnetoresistance is seen at tAu = 1 ML. I have also investigated the strain, surface alloying, and surface (interface) roughness of these systems using RHEED, XPS, and LAXD. Analysis of these measurements reveals some correlation between magnetic anisotropy and both strain and surface roughness. Based on my investigations, I conclude that the most likely cause for the non-monotonic changes seen in anisotropy is changes in the surface magnetocrystalline anisotropy. While strain and surface roughness may also play a role, I believe that the influence of the ultra-thin Au interlayer on the orbital hybridization and electronic environment at the interface is dominant.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Physics, Electricity and Magnetism.; Physics, Condensed Matter.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Optical Sciences
Degree Grantor:
University of Arizona
Advisor:
Falco, Charles M.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleInfluence of ultra-thin Au interface layers on the structure and magnetic anisotropy of Co filmsen_US
dc.creatorEickmann, James Thomas, 1970-en_US
dc.contributor.authorEickmann, James Thomas, 1970-en_US
dc.date.issued1998en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractI have investigated the influence of an ultra-thin Au interface layer on the magnetic anisotropy of Co-Pd and Co-Cu structures. Sandwich structures of the form X/Co/Y/Cu/Si(111), with (X, Y) = (Pd, Pd), (Au, Pd), (Pd, Au), (Cu, Cu), (Au, Cu), and (Cu, Au) were studied. For each structure, a Au layer of systematically varied thickness (t(Au)) was inserted at one Co interface. I also investigated Co/Pd and Co/Cu multilayer systems. For each Co-Pd sandwich structures a maximum is observed in the magnetic anisotropy for t(Au) = 1 to 1.5 atomic monolayer (ML). For the Co/Pd multilayer system, a maximum in coercivity occurs with tAu = 0.5 ML. For each Co-Cu sandwich structure except (X, Y) = (Cu, Au), a minimum in magnetic anisotropy is observed at t(Au) = 1 ML. For the Co/Cu multilayer system, a decrease in magnetoresistance was seen with increased tAu except in multilayers with a relatively thin Co layer thickness (∼3 ML) which display a peak in magnetoresistance is seen at tAu = 1 ML. I have also investigated the strain, surface alloying, and surface (interface) roughness of these systems using RHEED, XPS, and LAXD. Analysis of these measurements reveals some correlation between magnetic anisotropy and both strain and surface roughness. Based on my investigations, I conclude that the most likely cause for the non-monotonic changes seen in anisotropy is changes in the surface magnetocrystalline anisotropy. While strain and surface roughness may also play a role, I believe that the influence of the ultra-thin Au interlayer on the orbital hybridization and electronic environment at the interface is dominant.en_US
dc.description.noteDigitization note: p. 101 missing from paper original.-
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectPhysics, Electricity and Magnetism.en_US
dc.subjectPhysics, Condensed Matter.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorFalco, Charles M.en_US
dc.identifier.proquest9829374en_US
dc.identifier.bibrecord.b38554604en_US
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