Production and identification of flux-pinning defects by electron irradiation in YBa2Cu3O7-x single crystals.
Production and identification of flux-pinning defects by electron irradiation in YBa2Cu3O7-x single crystals.
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YBa2Cu3O7-x 单晶中电子辐照产生和识别通量钉扎缺陷。
DOI：
10.1103/physrevb.45.10677
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
M. Ruault
中科院分区：
文献类型：
--
作者：
J. Giapintzakis;Wei‐Cheng Lee;J. Rice;D. Ginsberg;I. Robertson;R. Wheeler;M. Kirk;M. Ruault
An enhancement in {ital J}{sub {ital c}} of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} single crystals in a magnetic field is observed after irradiation with 1-MeV electrons. Typically, a factor-of-2 increase in {ital J}{sub {ital c}} is deduced from magnetic hysteresis loops at 10 K and 1 T with {bold H}{parallel}{ital c}. This enhancement is about 1/2 of that produced by proton and neutron irradiations under similar measurement conditions. {ital In} {ital situ} transmission-electron-microscopy studies found no visible defects induced by electron irradiation, which means that point defects or small clusters (of size {lt}2 nm) are responsible for the extra pinning. Annealing studies suggest that effective pinning centers for {bold H}{parallel}{ital c} do not include oxygen vacancies in the Cu-O chains. Based on calculations of cross sections for displacements on the different sublattices, and in conjunction with the results of a {ital J}{sub {ital c}} calculation by Kes, we suggest that the most likely pinning defect is the displacement of a Cu atom from the CuO{sub 2}-plane sites.
An enhancement in {ital J}{sub {ital c}} of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} single crystals in a magnetic field is observed after irradiation with 1-MeV electrons. Typically, a factor-of-2 increase in {ital J}{sub {ital c}} is deduced from magnetic hysteresis loops at 10 K and 1 T with {bold H}{parallel}{ital c}. This enhancement is about 1/2 of that produced by proton and neutron irradiations under similar measurement conditions. {ital In} {ital situ} transmission-electron-microscopy studies found no visible defects induced by electron irradiation, which means that point defects or small clusters (of size {lt}2 nm) are responsible for the extra pinning. Annealing studies suggest that effective pinning centers for {bold H}{parallel}{ital c} do not include oxygen vacancies in the Cu-O chains. Based on calculations of cross sections for displacements on the different sublattices, and in conjunction with the results of a {ital J}{sub {ital c}} calculation by Kes, we suggest that the most likely pinning defect is the displacement of a Cu atom from the CuO{sub 2}-plane sites.