Growth of superconducting SmFeAs(O, F) epitaxial films by F diffusion
Growth of superconducting SmFeAs(O, F) epitaxial films by F diffusion
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F扩散法生长超导SmFeAs(O, F)外延薄膜
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
Michio Naito
中科院分区：
文献类型：
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作者：
Soichiro Takeda;S. Ueda;Shiro Takano;Akiyasu Yamamoto;Michio Naito
报道了用F扩散法生长SmFeAs(O，F)超导薄膜。在我们的过程中，首先通过分子束外延(MBE)生长了无F的SmFeAsO薄膜，然后通过F扩散从SmF3的覆盖层向薄膜中引入F。我们比较了CaF_2和LaAl_3衬底的生长条件和所得薄膜的性质。在CaF2衬底上生长的薄膜表现出较高的转变温度，最高转变温度K(56.4K)，这可能超过体相样品的最高转变温度。此外，在5K的自电场下，CaF_2衬底薄膜的临界电流密度也高于1 MA cm−_2，而LaAl_3衬底薄膜的临界电流密度为50.3K(49.3K)。LaAlO_3的超导性能恶化似乎是由于氧从LaAl_3扩散到薄膜中所致。
We report on our growth of superconducting SmFeAs(O, F) films by F diffusion. In our process, F-free SmFeAsO films were grown by molecular beam epitaxy (MBE) first, and subsequently F was introduced to the films via F diffusion from an overlayer of SmF3. We compared the growth conditions and also the properties of resultant films for CaF2 and LaAlO3 substrates. The best films on CaF2 exhibited a high transition temperature, K (56.4 K) at the highest, which may exceed the highest Tc ever reported for bulk samples. Furthermore, the films on CaF2 also showed high critical current density over 1 MA cm−2 in self-field at 5 K. On the other hand, the of the film on LaAlO3 was 50.3 K (49.3 K). The deteriorated superconducting properties on LaAlO3 appear to be due to oxygen diffusion from LaAlO3 to films.