Vortex liquid entanglement in irradiated YBa2Cu3O7 thin films -: art. no. 064503
Vortex liquid entanglement in irradiated YBa2Cu3O7 thin films -: art. no. 064503
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DOI：
10.1103/physrevb.63.064503
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发表时间：
2001-02-01
影响因子：
3.7
通讯作者：
Vicent, JL
中科院分区：
文献类型：
--
作者：
Sefrioui, Z;Arias, D;Vicent, JL
用高压去溅射法生长的YBa_2Cu_3 O_7外延薄膜，在80 keV的He ~+离子辐照下，剂量在10（14）~ 10（15）cm ~（-2）之间。辐射降低了临界温度，但它不改变载流子浓度。依赖于角度的电阻率被用来表明，质量各向异性不改变照射后。I-V临界标度分析了在平行于c轴的磁场中的熔融转变，所有辐照和未辐照样品均表现出具有相同临界指数的三维涡旋玻璃化转变。在液体状态下的耗散进行了分析，在垂直磁场中的磁电阻的激活能。虽然生长的样品显示的激活能依赖于1/H上施加的磁场，照射的样品显示的依赖性为1/HO 0.5，特征的塑性变形的旋涡。这是讨论的离子辐照引入的点无序。
Epitaxial YBa2Cu3O7 thin films, grown by high-pressure de sputtering, an irradiated with He+ ions at 80 keV with doses between 10(14) and 10(15) cm(-2). Irradiation reduces the critical temperature but it does not modify the carrier concentration. Angle-dependent resistivity is used to show that the mass anisotropy does not change upon irradiation. The melting transition in magnetic fields applied parallel to the c axis is analyzed by I-V critical scaling, and all irradiated and nonirradiated samples show a three-dimensional vortex glass transition with the same critical exponents. The dissipation in the liquid state is analyzed in terms of the activation energy of the magnetoresistance in a perpendicular magnetic field. While as-grown samples show an activation energy depending as l/H on the applied magnetic field, irradiated samples show a dependence as l/HO0.5, characteristic of plastic deformation of vortices. This is discussed in terms of the point disorder introduced by ion irradiation.