Buffer Layers for Tl-2212 Thin Films on MgO and
Buffer Layers for Tl-2212 Thin Films on MgO and
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DOI：
10.1109/tasc.2003.812393
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发表时间：
2003-07
期刊：
影响因子：
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通讯作者：
Sapphire Substrates;S. Speller;Houzheng Wu;C. Grovenor
中科院分区：
文献类型：
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作者：
Sapphire Substrates;S. Speller;Houzheng Wu;C. Grovenor
高质量的Tl-2212薄膜可以很容易地生长在LaAlO衬底上，但由于衬底的孪生，在这些薄膜中设计复杂的微波器件变得更加困难。蓝宝石上的CeO缓冲层已被证明为Tl-2212膜提供优异的衬底（1）。我们一直在探索MgO和蓝宝石上缓冲层的替代架构。用溅射沉积无铊前驱体和非原位铊化退火的方法，在Gd O缓冲MgO衬底上成功地生长了Tl-2212超导薄膜。Tl-2212薄膜与垂直于薄膜表面的-轴对齐，并且也具有良好的面内取向，其中Tl-2212与Gd O和MgO对齐。薄膜的临界温度范围为100-103 K，在77 K时的输运和感应临界电流密度为7.5 × 10 ~（-1）A/cm ~ 2。我们还在蓝宝石衬底上制备了外延GdAlO缓冲层，其支持Tl-2212的外延生长，但具有相对较差的微观结构。在新型La，Sr，Al，TaO（LSAT）衬底上制备了高质量的薄膜.
High quality Tl-2212 films can be readily grown on LaAlO substrates, but the design of complex microwave devices in these films is made more difficult by the twinning of the substrate. CeO buffer layers on sapphire have been demonstrated to offer excellent substrates for Tl-2212 films (1). We have been exploring alternative architectures for buffer layers on MgO and sapphire. Epitaxial Tl-2212 superconducting thin films have been success- fully grown on Gd O -buffered MgO substrates by sputter deposi- tion of a Tl-free precursor followed by an ex-situ thalliation anneal. The Tl-2212 films were aligned with the -axis normal to the film surface, and also had excellent in-plane orientation with Tl-2212 aligned with the Gd O and MgO . The critical tem- peratures of the films ranged from 100-103 K and transport and inductive critical current densities of 7.5 10 A/cm at 77 K have been achieved. We have also fabricated epitaxial GdAlO buffer layers on sapphire substrates which support epitaxial growth of Tl-2212 but with relatively poor microstructure. High quality films have been prepared on the new La,Sr Al,Ta O (LSAT) sub- strates.