Abstract
The ratio of coherent twin boundary energy to surface energy has been measured for annealing twins in platinum and cobalt over the temperature ranges 920–1560°c and 880–1290°c respectively. For platinum the ratio decreases from 0°060 at 920°c to 0°016 (extrapolated) at the melting point, whereas for cobalt the temperature variation is less than the experimental error. Possible values for the surface energy and its temperature dependence are discussed and estimates of the temperature dependence of the twin boundary energy are made.