Pub Date : 2004-12-27DOI: 10.1103/PhysRevB.71.104513
M. Crawford, R. Harlow, S. Deemyad, V. Tissen, J. Schilling, E. Mccarron, S. Tozer, D. Cox, N. Ichikawa, S. Uchida, Q. Huang
We have determined the crystal structures and superconducting transition temperatures of La1.48Nd0.4Sr0.12CuO4 under nearly hydrostatic pressures in diamond anvil cells to 5.0 GPa and 19.0 GPa, respectively. Synchrotron x-ray powder diffraction measurements were used to establish the pressure-temperature structural phase diagram. Under pressure the superconducting transition temperature increases rapidly from Tc = 3 K to a maximum value of 22 K at 5 GPa, a pressure slightly greater than that required to stabilize the undistorted I4/mmm structure in the superconducting state. Increasing the pressure further to 19 GPa leads to a decrease in Tc to ~12 K. These results are discussed in relation to earlier high pressure measurements for similar materials.
{"title":"HIGH-PRESSURE STUDY OF STRUCTURAL PHASE TRANSITIONS AND SUPERCONDUCTIVITY IN LA1.48ND0.4SR0.12CUO4","authors":"M. Crawford, R. Harlow, S. Deemyad, V. Tissen, J. Schilling, E. Mccarron, S. Tozer, D. Cox, N. Ichikawa, S. Uchida, Q. Huang","doi":"10.1103/PhysRevB.71.104513","DOIUrl":"https://doi.org/10.1103/PhysRevB.71.104513","url":null,"abstract":"We have determined the crystal structures and superconducting transition temperatures of La1.48Nd0.4Sr0.12CuO4 under nearly hydrostatic pressures in diamond anvil cells to 5.0 GPa and 19.0 GPa, respectively. Synchrotron x-ray powder diffraction measurements were used to establish the pressure-temperature structural phase diagram. Under pressure the superconducting transition temperature increases rapidly from Tc = 3 K to a maximum value of 22 K at 5 GPa, a pressure slightly greater than that required to stabilize the undistorted I4/mmm structure in the superconducting state. Increasing the pressure further to 19 GPa leads to a decrease in Tc to ~12 K. These results are discussed in relation to earlier high pressure measurements for similar materials.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"10 1","pages":""},"PeriodicalIF":16.8,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/PhysRevB.71.104513","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61866023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synchrotron-based x-ray microbeam fluorescence and diffraction have been used for in situ measurements of Cu concentration and biaxial stress in a 200-μm-long, 10-μm-wide Al(0.25 at. % Cu) conductor line with 1.5-μm-thick SiO2 passivation during electromigration. Measurements over 48 h with T=300 °C and j=1.5×105 A/cm2 show that a stress gradient of 3 MPa/μm develops over the upstream 130 μm of line length where Cu concentration drops below 0.15 at. %, and a 10-μm-long void develops at the cathode end of the line, but little change in stress occurs over the downstream 70 μm of line length where Cu concentration remains above 0.15 at. %. These experimental results have been reproduced by a finite element model in which the downstream Cu transport is accompanied by a counter flow of Al in the upstream direction, and downstream Al motion is blocked where the local Cu concentration is above ∼0.15 at. %. Defect mediated coupling between Al and Cu diffusive flows, e.g., Cu–vacancy binding, is proposed as the ca...
{"title":"RELATIONSHIP BETWEEN COPPER CONCENTRATION AND STRESS DURING ELECTROMIGRATION IN AN A1(0.25 AT % CU) CONDUCTOR LINE","authors":"H. Kao, G. Cargill, F. Giuliani, C. Hu","doi":"10.1063/1.1539282","DOIUrl":"https://doi.org/10.1063/1.1539282","url":null,"abstract":"Synchrotron-based x-ray microbeam fluorescence and diffraction have been used for in situ measurements of Cu concentration and biaxial stress in a 200-μm-long, 10-μm-wide Al(0.25 at. % Cu) conductor line with 1.5-μm-thick SiO2 passivation during electromigration. Measurements over 48 h with T=300 °C and j=1.5×105 A/cm2 show that a stress gradient of 3 MPa/μm develops over the upstream 130 μm of line length where Cu concentration drops below 0.15 at. %, and a 10-μm-long void develops at the cathode end of the line, but little change in stress occurs over the downstream 70 μm of line length where Cu concentration remains above 0.15 at. %. These experimental results have been reproduced by a finite element model in which the downstream Cu transport is accompanied by a counter flow of Al in the upstream direction, and downstream Al motion is blocked where the local Cu concentration is above ∼0.15 at. %. Defect mediated coupling between Al and Cu diffusive flows, e.g., Cu–vacancy binding, is proposed as the ca...","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"12 1","pages":""},"PeriodicalIF":16.8,"publicationDate":"2003-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.1539282","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58224107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Publishers have varying policies as to when published articles become freely available to the public, but it seems that within any one publishing group the free access policy should be the same for all authors.
{"title":"Some more equal than others.","authors":"L. Rogers","doi":"10.7748/ns.6.43.41.s43","DOIUrl":"https://doi.org/10.7748/ns.6.43.41.s43","url":null,"abstract":"Publishers have varying policies as to when published articles become freely available to the public, but it seems that within any one publishing group the free access policy should be the same for all authors.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"14 4 1","pages":"251"},"PeriodicalIF":16.8,"publicationDate":"1992-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71384518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Publishers have varying policies as to when published articles become freely available to the public, but it seems that within any one publishing group the free access policy should be the same for all authors.
{"title":"Some more equal than others","authors":"J. Petts","doi":"10.7748/ns.5.40.42.s51","DOIUrl":"https://doi.org/10.7748/ns.5.40.42.s51","url":null,"abstract":"Publishers have varying policies as to when published articles become freely available to the public, but it seems that within any one publishing group the free access policy should be the same for all authors.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"185 1","pages":"251-251"},"PeriodicalIF":16.8,"publicationDate":"1991-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74604692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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