Critical thickness and effective thermal expansion coefficient of YBCO crystalline film
Critical thickness and effective thermal expansion coefficient of YBCO crystalline film
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DOI：
10.1016/s0921-4534(98)00350-5
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发表时间：
1998-09-10
期刊：
影响因子：
1.7
通讯作者：
Hirabayashi, I
中科院分区：
文献类型：
--
作者：
Kawashima, J;Yamada, Y;Hirabayashi, I
采用液相外延法（LPE）确定了在SrTiO3 （STO）衬底上沉积YBCO晶膜裂纹形成的临界厚度。制备的薄膜，即使厚度超过4 μ m，也没有明显的裂纹，而氧退火的薄膜根据薄膜厚度的不同，裂纹扩展明显，因此估计临界厚度约为1.35 μ m，在MgO缓冲的STO衬底上形成的薄膜具有几乎相同的临界厚度。考虑衬底和YBCO薄膜的热膨胀，YBCO晶体薄膜的有效热膨胀系数为13.4 × 10(-6)/K，薄膜内部会产生拉应力和裂纹。(C) 1998 Elsevier Science B.V.版权所有
Critical thickness for crack formation has been determined for the YBCO crystalline film deposited on the SrTiO3 (STO) substrate by the liquid phase epitaxial (LPE) method. As-prepared films, even more than 4 mu m in thickness, have no visible cracks, while oxygen-annealed films show apparent crack propagation depending on the film thickness, leading to the estimation of critical thickness of about 1.35 mu m. Films formed on MgO buffered STO substrates have almost the same critical thickness. The effective thermal expansion coefficient of YBCO crystalline film has been deduced to be 13.4 x 10(-6)/K by considering thermal expansion of the substrate and the YBCO film, which causes internal tensile stress and crack formation in the film. (C) 1998 Elsevier Science B.V. All rights reserved.