EFFECT OF COMPRESSIVE UNIAXIAL STRESS ON HIGH FIELD DOMAINS IN n-TYPE Ge

The effect of compressive uniaxial stress on the threshold field for nucleation of high field domains in n-type Ge at 27°K has been measured. The increase in threshold field is approximately quadratic in stress and is about 15% for a stress of 104 kg/cm2 applied along a 〈100〉 direction parallel to the current and about 37% for a stress of 104 kg/cm2 applied along a 〈100〉 perpendicular to the current. These results indicate that, while in a strong electric field the 〈110〉 valleys are occupied at high stresses, transfer of electrons to these valleys is not the cause of bulk negative differential conductivity in n-type Ge.