Effect of Phase Transformations on Hardness of Semiconductors

ABSTRACTModels that describe hardness of materials do not account for stress-induced phase transformations that occur under sharp indenters. However, experimental work shows that some materials can be transformed under the indenter into new, high-pressure phases with properties that differ significantly from those of the pristine material. In particular, semiconductors (Si, Ge and other) experience Herzfeld-Mott transition (metallization). Significant volume changes can accompany these transformations. In the present paper, Tanaka's model [1] has been modified to account for reversible phase transformations under contact loading.