{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22155"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22155","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Magnetic properties of the rare earth systems neodymium/yttrium and dysprosium/yttrium","abstract":"We have studied a series of Nd/Y films and superlattices, grown by molecular beam epitaxy (MBE), using neutron, x-ray, and bulk magnetization techniques. These epitaxial Nd/Y systems are the first to be grown and studied which incorporate a light rare earth (RE) element. Using neutron diffraction, we have found that a portion of the Nd moment in the superlattices orders in a c-axis helical phase that does not exist in bulk. The helimagnetic turn angle decreases from $\\rm{\\sim}60\\sp\\circ$/atomic layer just below T$\\rm\\sb{N},$ to nearly antiferromagnetic coupling between same-symmetry site layers (90$\\sp\\circ$/at. layer) in the low-temperature limit. The ordering temperature of the helimagnetic phase is $\\sim$30 K, an enhancement of about 50% over the bulk T$\\rm \\sb{N}$ of 19.9 K. As the Nd films or superlattice interlayers become thicker, the magnetic moments of the sample increasingly tend to order in basal-plane modulated phases, similar to those seen in bulk; for a thick 5825 A Nd film, only basal-plane modulated magnetic order was observed. We expect that the formation of the c-axis helical phase in the Nd/Y superlattices is due to hybridization of the band structure in these systems, rather than to epitaxial strain-induced effects. We have also studied a heavy RE allow using x-ray resonant magnetic scattering. We have used this technique to detect, for the first time, the presence of the induced spin-density wave in the conduction band of nonmagnetic Lu atoms which are alloyed in a helimagnetic Dy host lattice. By tuning the incident synchrotron x-ray energy to the L$\\rm\\sb{III}$ edges of both Dy and Lu, we were able to use the species-sensitivity of x-ray resonant magnetic scattering to isolate the contribution from each element individually. As there are no unfilled f-levels on Lu atoms, the intensity observed at the magnetic wavevector that is resonant at the Lu edge reflects the polarization of the 5d electrons, which support a spin-density wave of $\\rm{\\sim}0.1\\ \\mu\\sb{B}/$atom in the Dy$\\sb{0.6}$Lu$\\sb{0.4}$ thin film alloy.","abstract_html":"We have studied a series of Nd/Y films and superlattices, grown by molecular beam epitaxy (MBE), using neutron, x-ray, and bulk magnetization techniques. These epitaxial Nd/Y systems are the first to be grown and studied which incorporate a light rare earth (RE) element. Using neutron diffraction, we have found that a portion of the Nd moment in the superlattices orders in a c-axis helical phase that does not exist in bulk. The helimagnetic turn angle decreases from $\\rm{\\sim}60\\sp\\circ$/atomic layer just below T$\\rm\\sb{N},$ to nearly antiferromagnetic coupling between same-symmetry site layers (90$\\sp\\circ$/at. layer) in the low-temperature limit. The ordering temperature of the helimagnetic phase is $\\sim$30 K, an enhancement of about 50% over the bulk T$\\rm \\sb{N}$ of 19.9 K. As the Nd films or superlattice interlayers become thicker, the magnetic moments of the sample increasingly tend to order in basal-plane modulated phases, similar to those seen in bulk; for a thick 5825 A Nd film, only basal-plane modulated magnetic order was observed. We expect that the formation of the c-axis helical phase in the Nd/Y superlattices is due to hybridization of the band structure in these systems, rather than to epitaxial strain-induced effects. We have also studied a heavy RE allow using x-ray resonant magnetic scattering. We have used this technique to detect, for the first time, the presence of the induced spin-density wave in the conduction band of nonmagnetic Lu atoms which are alloyed in a helimagnetic Dy host lattice. By tuning the incident synchrotron x-ray energy to the L$\\rm\\sb{III}$ edges of both Dy and Lu, we were able to use the species-sensitivity of x-ray resonant magnetic scattering to isolate the contribution from each element individually. As there are no unfilled f-levels on Lu atoms, the intensity observed at the magnetic wavevector that is resonant at the Lu edge reflects the polarization of the 5d electrons, which support a spin-density wave of <span class=\"etd-inline-math\">\\rm{\\sim}0.1 &mu;\\sb{B}/</span>atom in the Dy$\\sb{0.6}$Lu$\\sb{0.4}$ thin film alloy.","abstract_has_math":true,"creators":["Everitt, Brenda Anne"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Salamon, Myron B."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:30:45Z","date_published":"2011-05-07T13:30:45Z","updated_at":"2026-07-22T22:25:19Z","subjects":["Physics, Condensed Matter"],"languages":["eng"],"rights":["Copyright 1995 Everitt, Brenda Anne"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9624342","(UMI)AAI9624342"],"render_values":[{"text":"AAI9624342","href":null,"code":true},{"text":"(UMI)AAI9624342","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22155","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Salamon, Myron B."]},{"key":"dc:creator","label":"Author","values":["Everitt, Brenda Anne"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:30:45Z","10000-01-01","1995"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics, Condensed Matter"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1995 Everitt, Brenda Anne"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9624342","(UMI)AAI9624342","http://hdl.handle.net/2142/22155"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["We have studied a series of Nd/Y films and superlattices, grown by molecular beam epitaxy (MBE), using neutron, x-ray, and bulk magnetization techniques. These epitaxial Nd/Y systems are the first to be grown and studied which incorporate a light rare earth (RE) element. Using neutron diffraction, we have found that a portion of the Nd moment in the superlattices orders in a c-axis helical phase that does not exist in bulk. The helimagnetic turn angle decreases from $\\rm{\\sim}60\\sp\\circ$/atomic layer just below T$\\rm\\sb{N},$ to nearly antiferromagnetic coupling between same-symmetry site layers (90$\\sp\\circ$/at. layer) in the low-temperature limit. The ordering temperature of the helimagnetic phase is $\\sim$30 K, an enhancement of about 50% over the bulk T$\\rm \\sb{N}$ of 19.9 K. As the Nd films or superlattice interlayers become thicker, the magnetic moments of the sample increasingly tend to order in basal-plane modulated phases, similar to those seen in bulk; for a thick 5825 A Nd film, only basal-plane modulated magnetic order was observed. We expect that the formation of the c-axis helical phase in the Nd/Y superlattices is due to hybridization of the band structure in these systems, rather than to epitaxial strain-induced effects. We have also studied a heavy RE allow using x-ray resonant magnetic scattering. We have used this technique to detect, for the first time, the presence of the induced spin-density wave in the conduction band of nonmagnetic Lu atoms which are alloyed in a helimagnetic Dy host lattice. By tuning the incident synchrotron x-ray energy to the L$\\rm\\sb{III}$ edges of both Dy and Lu, we were able to use the species-sensitivity of x-ray resonant magnetic scattering to isolate the contribution from each element individually. As there are no unfilled f-levels on Lu atoms, the intensity observed at the magnetic wavevector that is resonant at the Lu edge reflects the polarization of the 5d electrons, which support a spin-density wave of $\\rm{\\sim}0.1\\ \\mu\\sb{B}/$atom in the Dy$\\sb{0.6}$Lu$\\sb{0.4}$ thin film alloy.","Made available in DSpace on 2011-05-07T13:30:45Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9624342.pdf: 6254703 bytes, checksum: a83a41787c0183a71b498e20970ddc50 (MD5) Previous issue date: 1995","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:55:42Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:25:59-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Magnetic properties of the rare earth systems neodymium/yttrium and dysprosium/yttrium"]}]}],"canonical_facts":{"dc:contributor":["Salamon, Myron B."],"dc:creator":["Everitt, Brenda Anne"],"dc:date":["2011-05-07T13:30:45Z","10000-01-01","1995"],"dc:description":["We have studied a series of Nd/Y films and superlattices, grown by molecular beam epitaxy (MBE), using neutron, x-ray, and bulk magnetization techniques. These epitaxial Nd/Y systems are the first to be grown and studied which incorporate a light rare earth (RE) element. Using neutron diffraction, we have found that a portion of the Nd moment in the superlattices orders in a c-axis helical phase that does not exist in bulk. The helimagnetic turn angle decreases from $\\rm{\\sim}60\\sp\\circ$/atomic layer just below T$\\rm\\sb{N},$ to nearly antiferromagnetic coupling between same-symmetry site layers (90$\\sp\\circ$/at. layer) in the low-temperature limit. The ordering temperature of the helimagnetic phase is $\\sim$30 K, an enhancement of about 50% over the bulk T$\\rm \\sb{N}$ of 19.9 K. As the Nd films or superlattice interlayers become thicker, the magnetic moments of the sample increasingly tend to order in basal-plane modulated phases, similar to those seen in bulk; for a thick 5825 A Nd film, only basal-plane modulated magnetic order was observed. We expect that the formation of the c-axis helical phase in the Nd/Y superlattices is due to hybridization of the band structure in these systems, rather than to epitaxial strain-induced effects. We have also studied a heavy RE allow using x-ray resonant magnetic scattering. We have used this technique to detect, for the first time, the presence of the induced spin-density wave in the conduction band of nonmagnetic Lu atoms which are alloyed in a helimagnetic Dy host lattice. By tuning the incident synchrotron x-ray energy to the L$\\rm\\sb{III}$ edges of both Dy and Lu, we were able to use the species-sensitivity of x-ray resonant magnetic scattering to isolate the contribution from each element individually. As there are no unfilled f-levels on Lu atoms, the intensity observed at the magnetic wavevector that is resonant at the Lu edge reflects the polarization of the 5d electrons, which support a spin-density wave of $\\rm{\\sim}0.1\\ \\mu\\sb{B}/$atom in the Dy$\\sb{0.6}$Lu$\\sb{0.4}$ thin film alloy.","Made available in DSpace on 2011-05-07T13:30:45Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9624342.pdf: 6254703 bytes, checksum: a83a41787c0183a71b498e20970ddc50 (MD5) Previous issue date: 1995","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:55:42Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:25:59-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9624342","(UMI)AAI9624342","http://hdl.handle.net/2142/22155"],"dc:language":["eng"],"dc:rights":["Copyright 1995 Everitt, Brenda Anne"],"dc:subject":["Physics, Condensed Matter"],"dc:title":["Magnetic properties of the rare earth systems neodymium/yttrium and dysprosium/yttrium"],"dc:type":["text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:19Z"}