Probing the phase diagram of cuprates with YBa2Cu3O7-δ thin films and nanowires
Probing the phase diagram of cuprates with YBa2Cu3O7-δ thin films and nanowires
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DOI：
10.1103/physrevmaterials.2.024804
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发表时间：
2018-02-28
影响因子：
3.4
通讯作者：
Lombardi, Floriana
中科院分区：
文献类型：
--
作者：
Arpaia, Riccardo;Andersson, Eric;Lombardi, Floriana
我们用脉冲激光沉积的方法在MgO(110)和SrTiO_3(001)衬底上生长并表征了30 nm厚的YBa2Cu3O7-Delta(YBCO)薄膜，该薄膜引起了与超导层相反的应变。通过仔细地调节原位后退火氧压，我们以一种可重复的方式获得了不同氧掺杂下的薄膜，从相图上的轻微过度掺杂一直到强烈欠掺杂区域。通过电阻对温度的测量，研究了薄膜的输运性质，与单晶的输运性质完全一致。从这些薄膜出发，我们还成功地在不同的氧掺杂条件下制备了宽度为65 nm的纳米线。纳米结构的特征温度(如临界温度T-c和伪隙温度T*)与生长的薄膜相似，其临界电流密度J(C)接近临界脱配值，受涡旋进入的限制。这意味着我们的薄膜中保留了欠掺杂YBCO的超导性质和正常态性质，并且它们可以作为系统维度的函数进行研究，甚至可以研究到纳米尺度。
We have grown and characterized 30-nm-thick YBa2Cu3O7-delta (YBCO) films, deposited by pulsed laser deposition on both MgO (110) and SrTiO3 (001) substrates, which induce opposite strain to the superconducting layer. By carefully tuning the in situ post-annealing oxygen pressure, we achieved, in a reproducible way, films at different oxygen doping, spanning from the slightly overdoped down to the strongly underdoped region of the phase diagram. The transport properties of the films, investigated through resistance versus temperature measurements, are in perfect qualitative agreement with single crystals. Starting from these films, we have also successfully fabricated nanowires with widths down to 65 nm, at different oxygen doping. The nanostructures exhibit characteristic temperatures (as the critical temperature T-c and the pseudogap temperature T*) similar to those of the as-grown films and carry critical current densities J(c) close to the critical depairing value, limited by vortex entry. This implies that the superconducting and the normal state properties of underdoped YBCO are preserved in our films, and they can be studied as a function of the dimensionality of the system, down to the nanoscale.