化学溶液法在LaAlO_3单晶基体上制备YBa_2Cu_3O_(7-x)薄膜的研究

Study of YBCO Films on LaAlO_3 Substrate Prepared by Chemical Solution Method

采用三氟乙酸盐-金属有机沉积(TFA-MOD)法在LaAlO3单晶基体上成功地制备了YBa2Cu3O7-x超导薄膜(简称YBCO薄膜),并比较系统地研究了烧结温度对YBCO薄膜的影响。在烧结温度为820℃时,所制备的YBCO薄膜完全呈c-轴取向,无a-轴取向的晶粒和杂质相存在,YBCO薄膜的表面无裂纹存在,表面平整,超导转变温度Tc≈90K,转变宽度ΔTc=1K,临界电流密度(Jc)可达1.2MA.cm-2(77K,0T)。

YBa2Cu3O7-x （YBCO） films were deposited on LaAlO3（LAO） substrate by the metalorganic deposition （ MOD ） method using trifluoroacetates （ TFA ） under the processing condition of various sintering temperature for crystallization. The superconducting characteristics were evaluated for the resulted films. The effect of sintering temperature on the characteristics of the films was studied systematically. Critical current density （ Jc ） was measured using jc-sean Leipzig system to compare the electrical properties of the films. Scanning electron microscopy （SEM） and X-ray diffraction （XRD） were used to determine the microstructure and orientation of the films. The films sintered at 820 ℃ showed the highest Tc value of 90 K and Jc of 1.2 MA·cm^-2. These highest critical properties were attributed to the formation of a purer （00l） YBCO phase and stronger biaxial texture.