Extremely accurate measurements of the thermal expansion along the principal directions of zinc single crystals were made at 45 to 410C by means of a dilatometric technique. The results seemed to indicate rather large inward displacements parallel to the c axis of atoms surrounding vacancies, and possibly a large anisotropy in the rearrangement of atoms during vacancy formation. An extra volumetric thermal expansion at high temperatures indicated a vacancy energy of formation of 0.50eV, and an entropy of formation of 2.30k.

Thermal-Expansion Measurements of Vacancy Formation Parameters in Zinc Single Crystals. H.M.Gilder, G.N.Wallmark: Physical Review, 1969, 182[3], 771-7