脉冲激光外延生长YBa_2Cu_3O_(7–δ)涂层导体LaMnO_3缓冲层

Epitaxial growth of LaMnO_3 buffer layers for YBa_2Cu_3O_(7-δ) coated conductors using pulsed laser deposition

采用脉冲激光沉积技术在双轴织构的Ni95W5(Ni-5W)合金基底上外延生长了LaMnO3(LMO)薄膜作为涂层导体缓冲层,研究了沉积温度对LMO薄膜生长织构和表面形貌的影响。研究结果表明:沉积温度对LMO薄膜的表面形貌有一定的影响;在沉积温度为650℃时,LMO薄膜具有良好的(00l)取向,薄膜表面平整均匀,光滑致密,其均方根粗糙度在2 nm以下;而且,在此LMO缓冲层上外延生长的YBa2Cu3O7–δ超导层具有良好的双轴织构,超导转变温度Tc为92 K,转变宽度小于1 K,临界电流密度Jc为5.3×105A/cm2(77 K,自场)。

LaMnO3 （LMO） thin films, as a single buffer layer of coated conductors, were epitaxially grown on the biaxially textured Ni95W5 （Ni-5W） alloy substrates by pulsed laser deposition （PLD）. The effects of deposition temperature on the growth texture and surface morphology of the LMO films were investigated. The results show that： the deposition temperature has some effect on the surface morphology of the LMO films. At a deposition temperature of 650℃, the prepared LMO film possesses perfect （00/） orientation and shows a flat, smooth, dense and uniform surface with the root mean square （RMS） roughness below 2 nm; Moreover, the YBa2Cu3O7-δ superconducting layer epitaxially grown on this LMO film exhibits a good biaxial texture, a superconducting transition temperature （To） of 92 K with the transition width below 1 K, and a critical current density （Jr） of 5.3×10^5 A/cm2 at 77 K in self-fields.