Interpretation of the Formation Volume of Defects in Crystal Growth

TL;DR

This paper clarifies that the formation volume of defects in crystal growth should be understood as a difference in volume between defective and perfect crystals, emphasizing the inseparability of these quantities in physical interpretation.

Contribution

It corrects a common misconception by emphasizing that defect formation volume is a difference, not separate volumes, in the context of crystal growth.

Findings

The formation volume is the difference between defective and perfect crystals.

Misinterpretation arises when defect and perfect crystal volumes are treated separately.

Proper interpretation affects calculations of defect formation enthalpy.

Abstract

In the calculation of the formation enthalpy of a defect, a stress term accompanying the formation volume of the defect appears. This formation volume is conventionally interpreted as the difference in volume between crystals with and without the defect. When defect formation is investigated in the study of crystal growth, the interpretation is sometimes misused by separately treating the volumes of the defect and perfect crystal. However, these two quantities are inseparable, and only the difference between them has physical reality.