摘要
用脉冲激光沉积法在斜切(001)SrTiO3单晶基片上生长了c轴取向的YBa2Cu3O7-δ超导薄膜,在斜切(001)LaAlO3单晶基片上生长了Ba0.1Sr0.9TiO3/YBa2Cu3O7-δ双层薄膜,并用扫描电镜和透射电镜对薄膜组织进行了表征.结果表明,在1°～3°斜切的SrTiO3基片上生长的YBa2Cu3O7-δ薄膜,呈现台阶流动(step flow)到三维岛状生长的转变;而6°～15°斜切基片上生长的YBa2Cu3O7-δ薄膜为完全台阶流动生长.在1.2°斜切的LaAlO3基片上原位制备了良好异质外延生长的Ba0.1Sr0.9TiO3/YBa2Cu3O7-δ双层薄膜.在77 K,1 MHz频率和±30 V直流偏压下,测定了其电容-电压特性,确定其介电常数、可调谐性和品质因数分别为1200,60%和133.表明该Ba0.1Sr0.9TiO3薄膜可应用于在液氮温度下工作的可调谐微波器件.
c-axis orientated YBa2Cu3O7-delta film and Ba0.1Sr0.9TiO3/YBa2Cu3O7-delta heterostructure films have been fabricated by pulsed laser deposition on miscut (001) SrTiO3 and (001) LaAlO3 substrates, respectively. Microstructures of the films have been characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results show that the YBa2Cu3O7-delta films grown on 1 degrees similar to 3 degrees miscut substrates display a step-flow crossover to three-dimensional island growths, and on 6 degrees similar to 15 degrees miscut substrates display a complete step flow growth. Perfect heteroepitaxial growth of Ba0.1Sr0.9TiO3/YBa2Cu3O7-delta on 1.2 degrees miscut (001) LaAlO3 has been in-situ achieved. A parallel-plate capacitor configuration is used to measure the capacitance-voltage properties of the Ba0.1Sr0.9TiO3 thin films under a dc bias of +/- 30 V and 1 MHz frequency at 77 K, and the dielectric constant, tenability and figure of merit are found to be 1200, 60%, and 133, respectively, confirming their usefulness for electrically tunable microwave devices at liquid nitrogen temperature.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2006年第4期542-545,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金重点基金资助(59832050)
