In situ HVEM study on copper oxidation using an improved environmental cell.
A window-type environmental cell that can be used over the temperature range from room temperature to approximately 1000 K was improved by incorporating a new window material that increases resolution and contrast in high voltage electron microscopy. With this improvement, the resolution was a few nanometers and the maximum pressure in the cell was approximately 1.3 x 10(4) Pa. Using this new window-type environmental cell, oxidation of copper and reduction of copper oxides, which occur through gas (oxygen or hydrogen)-solid (copper metal) reactions, have been successfully observed in situ, i.e. the formation process of oxides (Cu --> Cu2O --> CuO) and their subsequent reduction (CuO --> Cu) in the cell. The growth process of CuO whiskers on a thick (50 microm) Cu film was also observed in situ. It was found that whisker growth occurs at the tips of whiskers.
Department of Intelligence Machine, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 731-5193, Japan. komatsu@cc.it-hiroshima.ac.jp
Masao
M
Komatsu
Hirotaro
H
Mori