眞空管用マイカのガス放出
1954 年 23 巻 4 号 p. 150-152
詳細
1954 年 23 巻 4 号 p. 150-152
The mechanism of gas evolution from mica used for vacuum tube was studied. Experiments suggested that there are two sources of gas evolution: one is the surface contamination and the other is (OH)-, constituent of crystal network. The temperature at which mica becomes opaque was between 720°C_??_750°C and dehydration began to take place at lower temperatures. Experi-ments on the gas evolution from mica stripped off mechanically and thermally in vacuum showed that there was no fundamental relation between the opaque temperature and dehydration reaction. The evolution velocity of H2O from mica seems to increase in appearance at the temperature at which it becomes opaque since its exposed surface area becomes larger by thermal peeling off of crystal layer.
