Microscopic In-situ Evaluation of Corroding Surface of Film

在这项研究中，石英晶体微天平(QCM)、相位检测干涉显微镜(PDIM)的可用性。对激光共聚焦扫描显微镜(CLSM)和扫描电化学显微镜(SECM)这两种膜腐蚀表面微观原位评价的有力手段进行了较为详细的研究。QCM振动模式的频率分析表明，在空气中的临界相对湿度为30%时，金表面上的MgCl2盐膜的质量明显减少，这是由于QCM中的水被吸收到膜中，导致MgCl2膜从固体到液体的相变，从而减少了QCM的振动能量损失。在HF溶液中对p型硅表面进行化学腐蚀的PDIM观察表明，腐蚀速率取决于硅的比电阻率，表面粗糙度或表面形貌可以用…函数来定量地评价刻蚀时间越长离子越多。利用激光共聚焦显微镜(CLSM)对具有可见光的多孔硅层(PSL)的三维形貌进行了无损观察。同时，用CLSM对多孔硅层的发光形貌进行了同步测量，结果表明，可见光斑从整个PSL的深度发出均匀的可见光。SECM用于评价钛表面上形成的阳极氧化膜(TiO2)的缺陷位置。将包覆有二氧化钛薄膜的钛电极浸泡在含溴离子的H_2SO_4溶液中，将钛电极的电位控制在溴离子的氧化电位，则溴离子的氧化只在二氧化钛膜的缺陷位上进行，生成溴_2。同时，将电极电位控制在溴还原电位的碳纤维上，扫描钛电极表面，测量流过电极的阴极电流分布图。根据电流分布图可以确定二氧化钛薄膜缺陷的位置。SECM的应用仍在继续评估Fe钝化膜的均匀性。利用上述实验结果，可以全面了解QCM、PDIM、CSLM和SECM在膜层腐蚀表面微观原位评价中的适用性。较少

In this study, the availabilities of Quartz Crystal Microbalance(QCM), Phase Detection Interferometric Microscope (PDIM). Confocal Laser-Scanning Microscope (CLSM), and Scanning Electrochemical Microscope (SECM), which are regarded as powerful methods for microscopic in-situ evaluation of corroding surface of film, are examined more in detail.The frequency analysis of QCM vibration mode has revealed that the apparent decrease in mass of MgCl_2 salt film on gold at a critical relative humidity of 30 % in air results from the decrease in vibrational energy loss of QCM due to the phase transition of MgCl_2 film from solid to liquid which is caused by water absorption into the film, suggesting that QCM is promising as a sensor of phase transition.The PDIM observation of p-type Si surface subjected to chemical etching in HF solution has indicated that the etching rate depends on the specific resistivity of Si and the surface roughness or topography can be evaluated quantitatively as a funct … More ion of etching time. It has been also observed with PDIM that small spots are randomly distributed on electropolished aluminum surface and are associated with defects in the anodic oxide film formed subsequently on the electropolished surface.The application of CLSM to a porous Si layr (PSL) with visible luminescence has succeeded in observing nondestructively the three-dimensional morphology of PSL.The simultaneous measurement of the corresponding luminescensce morphology with CLSM has revealed that the visible luminescence emits uniformly from the whole depth of PSL.The SECM has been applied to evaluate the defect site of anodic oxide film (TiO_2) formed on Ti. When Ti electrode covered with TiO_2 film was immersed in H_2SO_4 solution containing Br^-ions and the potential of the Ti electrode was controlled at the potential of oxidation of Br^-ions, the oxidation of Br^-ions proceeded only on the defect site of TiO_2 film to produce Br_2. Simultaneously, the probe electrode (carbon fiber), the potential of which was controlled at the potential of reduction of Br_2, was scanned just over the Ti electrode surface to measure the distribution map of cathodic current flowed through the probe electrode. The location of defect site of TiO_2 film could be determined from the current distribution map. The application of SECM still continues to evaluate the uniformity of passive film on Fe.The comprehensive understanding of the availabilities of QCM,PDIM,CSLM,and SECM for microscopic in-situ evaluation of corroding surface of film could be performed with the above experimental results. Less