Growth of Copper Crystals of Low Dislocation Density

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Abstract
A study was made of the perfection and the factors controlling perfection of copper crystals grown by a Bridgman technique. Crystals grown from 99.999+% and from (OFHC) copper were acid sawed and polished, and dislocation densities determined by etch pit techniques. The orientation of the growth direction of unseeded crystals of both purities was random. There was a correlation between perfection and growth direction for the 99.999+% copper crystals in that the more perfect crystals had growth direction far from the [111] zone. Dislocation densities as low as 103/cm2, with no subboundaries, were obtained in some of the purer as‐grown crystals. The OFHC crystals were much less perfect and contained many subboundaries. After annealing slices of the purer crystals at 1075°C, dislocation densities as low as 102/cm2 were obtained. The vacancy condensation mechanism for dislocation generation apparently was not significant in accounting for the residual dislocation density in these crystals.