EQUILIBRIUM VACANCY CONCENTRATION MEASUREMENTS ON ZINC SINGLE-CRYSTALS

The formation parameters of vacancies in hexagonal zinc single crystals have been investigated by combined lattice parameter change and length change measurements. A maximum vacancy concentration at melting temperature of (C v)max=(4.9+or-0.3)*10-4 was found. The energy of formation and the entropy of formation for a single vacancy were determined to be E=(0.53+or-0.07)eV and s=(1.1+or-1) kB respectively. The creation of vacancies leads to a highly anisotropic volume change in zinc crystals. The ratio obtained from measurements in the a and c directions is ((Delta L/L)c-Delta c/ c)/((Delta L/L)a- Delta a/a)=5.7. Six times as many etch pits were found on a surface as on c surfaces. The authors concluded that in their zinc crystals, dislocations were preferentially oriented in the basal plane.