Method for determining changes in phase and defect concentration in solids

The material to be studied is placed into a sealed vessel made of nonconductive material to which 2 electrodes are connected. Pressure in the vessel is adjusted to a value in the range of 5x10-5 to 10-3 torrs and temperature is adjusted to -50 degC to +300 degC. Inert gas, possibly labelled with a radioactive isotope, is let into the vessel. After a pressure increase in the vessel to a value in the order of tens of torrs at the most, the gas supply is stopped and a voltage is applied across the electrodes ranging between 5 kV and 50 kV for 0.1 to 600 s. Unused gas is discharged from the vessel. The amount of gas released from the studied material in unit time as a result of a change in phase or in defect concentration is directly proportional to the intensity of structural changes or defect extent. If changes in the material are uneven the defect can thus be located. (J.P.)