The line tension which was associated with screw dislocations was considered. Firstly, it was shown that screw dislocations could be identified with negative line tensions on various cross-slip planes in cubic crystals. Analytical and numerical conditions for negative line tension were provided. Secondly, the relative magnitudes of the line tension on relevant cross-slip planes were calculated. The line tension on <100> and <111> screw dislocations was found to be fully independent of the cross-slip plane. However, that of (110) screw dislocations depended sensitively upon the cross-slip plane and was greatest on the cube cross-slip plane for most materials. A locking mechanism was proposed for elastically unstable screw dislocations.

Line Tension of Screw Dislocations on Cross-Slip Planes. Y.Q.Sun, A.H.W.Ngan: Philosophical Magazine Letters, 1996, 74[3], 175-87