{"id":{"repo_id":"tdl","oai_identifier":"oai:tdl-ir.tdl.org:1969.1/ETD-TAMU-2009-05-792"},"canonical_url":"https://search.dev.ndltd.org/etd/tdl/oai:tdl-ir.tdl.org:1969.1/ETD-TAMU-2009-05-792","repository":{"repo_id":"tdl","name":"Texas Digital Library","base_url":"https://tdl-ir.tdl.org/server/oai/request"},"display":{"title":"Extraction of Spin Polarization of Bulk and Measurement of Transport Properties of Thin GdxSi1-x Near the Metal-Insulator Transition","abstract":"Since the early 1960s, Abrikosov-Gorkov theory has been used to describe superconductors with paramagnetic impurities. Interestingly, the density of states resulting from the theoretical framework has to date only been known approximately, as a numeric solution of a complex polynomial. An analytical solution to the theory was discovered and applied to extract the spin polarization from the tunneling conductance of superconducting aluminium with 3-dimensional (3-D) amorphous (a-) gadoliniumxsilicon1-x (GdxSi1-x) as a counter electrode (Al/Al2O3/a-GdxSi1-x planar tunnel junction measured at T = 25 mK and H less than or equal to 3.0 T) in the quantum critical regime (QCR). The analytical solution is valid in the whole regime of Abrikosov-Gorkov theory independent of the presence of an energy gap. Applying the spin polarized Abrikosov-Gorkov theory to describe aluminium gives a larger spin polarization in GdxSi1-x than the spin polarized Bardeen-Cooper-Schrieffer (BCS) theory. The purpose of this study is to extract polarization at various applied magnetic fields, but no specific relationship between the two could be determined. Results obtained shows a transition from a superconductor with a gap to a gapless superconductor in varying external magnetic fields was observed. To improve understanding of GdxSi1-x near the metal-insulator transition (MIT) and compare it with prior work, the initial experimental attempts to investigate the transport property of GdxSi1-x near the MIT in the 2-dimensional limit are presented. A low temperature ultra high vacuum quench condensation system was used to make thin films of GdxSi1-x and in-situ measurements were performed. The transport properties for different values of x and thicknesses were measured for T = 4.2 K to ~10 K. In addition to other possible causes, the uncertainty in the electron impact emission spectroscopy (EIES) appeared to be a major reason behind the observed error in x when gadolinium and silicon are co-evaporated. The problems faced during the co-evaporation are also discussed.","abstract_html":"Since the early 1960s, Abrikosov-Gorkov theory has been used to describe superconductors with paramagnetic impurities. Interestingly, the density of states resulting from the theoretical framework has to date only been known approximately, as a numeric solution of a complex polynomial. An analytical solution to the theory was discovered and applied to extract the spin polarization from the tunneling conductance of superconducting aluminium with 3-dimensional (3-D) amorphous (a-) gadoliniumxsilicon1-x (GdxSi1-x) as a counter electrode (Al/Al2O3/a-GdxSi1-x planar tunnel junction measured at T = 25 mK and H less than or equal to 3.0 T) in the quantum critical regime (QCR). The analytical solution is valid in the whole regime of Abrikosov-Gorkov theory independent of the presence of an energy gap. Applying the spin polarized Abrikosov-Gorkov theory to describe aluminium gives a larger spin polarization in GdxSi1-x than the spin polarized Bardeen-Cooper-Schrieffer (BCS) theory. The purpose of this study is to extract polarization at various applied magnetic fields, but no specific relationship between the two could be determined. Results obtained shows a transition from a superconductor with a gap to a gapless superconductor in varying external magnetic fields was observed. To improve understanding of GdxSi1-x near the metal-insulator transition (MIT) and compare it with prior work, the initial experimental attempts to investigate the transport property of GdxSi1-x near the MIT in the 2-dimensional limit are presented. A low temperature ultra high vacuum quench condensation system was used to make thin films of GdxSi1-x and in-situ measurements were performed. The transport properties for different values of x and thicknesses were measured for T = 4.2 K to ~10 K. In addition to other possible causes, the uncertainty in the electron impact emission spectroscopy (EIES) appeared to be a major reason behind the observed error in x when gadolinium and silicon are co-evaporated. The problems faced during the co-evaporation are also discussed.","abstract_has_math":false,"creators":["Srivastava, Raj Vibhuti A."],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Teizer, Winfried"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-07-14","date_published":"2010-07-14","updated_at":"2026-08-21T22:21:56Z","subjects":["amorphous thin films","tunneling conductance","(gapless) superconductivity","Abrikosov Gorkov theory"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-792","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"source_record":{"url":"https://tdl-ir.tdl.org/server/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Atdl-ir.tdl.org%3A1969.1%2FETD-TAMU-2009-05-792","prefix":"dim"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Teizer, Winfried"]},{"key":"dc:creator","label":"Author","values":["Srivastava, Raj Vibhuti A."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2010-07-15T00:14:09Z","2010-07-23T21:45:36Z","2017-04-07T19:57:14Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2010-07-15T00:14:09Z","2010-07-23T21:45:36Z","2017-04-07T19:57:14Z"]},{"key":"dc:date.issued","label":"Date","values":["2010-07-14"]},{"key":"dc:type","label":"Dc Type","values":["Book","Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["amorphous thin films","tunneling conductance","(gapless) superconductivity","Abrikosov Gorkov theory"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-792"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Since the early 1960s, Abrikosov-Gorkov theory has been used to describe superconductors with paramagnetic impurities. Interestingly, the density of states resulting from the theoretical framework has to date only been known approximately, as a numeric solution of a complex polynomial. An analytical solution to the theory was discovered and applied to extract the spin polarization from the tunneling conductance of superconducting aluminium with 3-dimensional (3-D) amorphous (a-) gadoliniumxsilicon1-x (GdxSi1-x) as a counter electrode (Al/Al2O3/a-GdxSi1-x planar tunnel junction measured at T = 25 mK and H less than or equal to 3.0 T) in the quantum critical regime (QCR). The analytical solution is valid in the whole regime of Abrikosov-Gorkov theory independent of the presence of an energy gap. Applying the spin polarized Abrikosov-Gorkov theory to describe aluminium gives a larger spin polarization in GdxSi1-x than the spin polarized Bardeen-Cooper-Schrieffer (BCS) theory. The purpose of this study is to extract polarization at various applied magnetic fields, but no specific relationship between the two could be determined. Results obtained shows a transition from a superconductor with a gap to a gapless superconductor in varying external magnetic fields was observed. To improve understanding of GdxSi1-x near the metal-insulator transition (MIT) and compare it with prior work, the initial experimental attempts to investigate the transport property of GdxSi1-x near the MIT in the 2-dimensional limit are presented. A low temperature ultra high vacuum quench condensation system was used to make thin films of GdxSi1-x and in-situ measurements were performed. The transport properties for different values of x and thicknesses were measured for T = 4.2 K to ~10 K. In addition to other possible causes, the uncertainty in the electron impact emission spectroscopy (EIES) appeared to be a major reason behind the observed error in x when gadolinium and silicon are co-evaporated. The problems faced during the co-evaporation are also discussed."]},{"key":"dc:title","label":"Title","values":["Extraction of Spin Polarization of Bulk and Measurement of Transport Properties of Thin GdxSi1-x Near the Metal-Insulator Transition"]}]}],"canonical_facts":{"dc:contributor":["Teizer, Winfried"],"dc:creator":["Srivastava, Raj Vibhuti A."],"dc:date.accessioned":["2010-07-15T00:14:09Z","2010-07-23T21:45:36Z","2017-04-07T19:57:14Z"],"dc:date.available":["2010-07-15T00:14:09Z","2010-07-23T21:45:36Z","2017-04-07T19:57:14Z"],"dc:date.issued":["2010-07-14"],"dc:description.abstract":["Since the early 1960s, Abrikosov-Gorkov theory has been used to describe superconductors with paramagnetic impurities. Interestingly, the density of states resulting from the theoretical framework has to date only been known approximately, as a numeric solution of a complex polynomial. An analytical solution to the theory was discovered and applied to extract the spin polarization from the tunneling conductance of superconducting aluminium with 3-dimensional (3-D) amorphous (a-) gadoliniumxsilicon1-x (GdxSi1-x) as a counter electrode (Al/Al2O3/a-GdxSi1-x planar tunnel junction measured at T = 25 mK and H less than or equal to 3.0 T) in the quantum critical regime (QCR). The analytical solution is valid in the whole regime of Abrikosov-Gorkov theory independent of the presence of an energy gap. Applying the spin polarized Abrikosov-Gorkov theory to describe aluminium gives a larger spin polarization in GdxSi1-x than the spin polarized Bardeen-Cooper-Schrieffer (BCS) theory. The purpose of this study is to extract polarization at various applied magnetic fields, but no specific relationship between the two could be determined. Results obtained shows a transition from a superconductor with a gap to a gapless superconductor in varying external magnetic fields was observed. To improve understanding of GdxSi1-x near the metal-insulator transition (MIT) and compare it with prior work, the initial experimental attempts to investigate the transport property of GdxSi1-x near the MIT in the 2-dimensional limit are presented. A low temperature ultra high vacuum quench condensation system was used to make thin films of GdxSi1-x and in-situ measurements were performed. The transport properties for different values of x and thicknesses were measured for T = 4.2 K to ~10 K. In addition to other possible causes, the uncertainty in the electron impact emission spectroscopy (EIES) appeared to be a major reason behind the observed error in x when gadolinium and silicon are co-evaporated. The problems faced during the co-evaporation are also discussed."],"dc:identifier.uri":["http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-792"],"dc:language.iso":["eng"],"dc:subject":["amorphous thin films","tunneling conductance","(gapless) superconductivity","Abrikosov Gorkov theory"],"dc:title":["Extraction of Spin Polarization of Bulk and Measurement of Transport Properties of Thin GdxSi1-x Near the Metal-Insulator Transition"],"dc:type":["Book","Thesis"]},"updated_at":"2026-08-21T22:21:56Z"}