利用线性液膜的红外热像测定YBCO的湿法化学刻蚀启动时长

Measurement of Starting Duration of YBCO Wet Chemical Etching with Infrared Thermal Image of Linear Liquid Film

提出了一种测定YBCO（YBa2Cu3O7-x）高温超导薄膜湿法腐蚀启动时长的红外热像新方法。该方法的实质是利用YBCO腐蚀时必然有化学热吸收或释放,从而引起YBCO表面液膜温度变化这一特点,通过红外热像实时监测系统,采集液膜温度变化过程的红外热像,从而判断反应启动时长。理论分析和实验结果均表明,YBCO表面2 mm宽线性液膜是较为理想的监测对象,因其同时具备温度变化信息和空间分布信息,可以将线性液膜中心作为理想的观测特征点;由滑动腐蚀液滴形成残留线性液膜具有温度变化灵敏度高的特点,YBCO（衬底为LaAlO3）竖直放置,可以表面避免液膜重力对启动时长的影响,获得更为准确的监测数据。由线性液膜的横向剖面灰度变化得到在本实验条件下YBCO薄膜与体积比H3PO4∶H2O=1∶300腐蚀液的反应启动时长介于0.3-0.4 s之间。

A new infrared thermal image method to measure the starting duration of YBCO high-temperature superconductor （HTS） film chemical etching was proposed. The temperature variation of liquid film on YBCO surface was induced by absorption or release of chemical heat during etching of YBCO film, and the start time of reaction can be tested by real-time collection of the infrared thermal image in the course of liquid film temperature variation. Theoretical analysis and experimental results show that linear liquid film with 2 mm width is adtopted to monitor because all the information of temperature and space change is possessed, and the center of liquid film can be set as an observed character point. The more accurate experimental data can be obtained because of the high sensitivity of temperature change of extraordinary thin linear film made by sliding droplet. The influence of film weight on start time can be avoided with upright YBCO film （LaAlO3 substrate）. The start time of reaction between YBCO film and H3 PO4 ： H2O（ volume ratio 1 ： 300）liquid is about 0.3-0.4 s, which is obtained by the grey-scale variation of a certain cross section of linear liquid film.