Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. IV France 06 (1996) C8-285-C8-288
A Study of Self-Interstitial Atom in W by Means of Low-Temperature IrradiationsH. Tanimoto1, H. Mizubayashi1, H. Nishimura1 and S. Okuda2
1 Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305, Japan
2 Faculty of Engineering, Ibaraki University, Hitachi, Ibaraki 316, Japan
To clarify the migration behavior of self-interstitial atoms (SIA's) in W, we have performed anelasticity measurements of W after 2 MeV electron irradiation at 5 K and after 20 MeV proton irradiation at 1.5 K. Dislocation pinning results observed during irradiation clearly show that free SIA's in W migrate below 1.5 K. Warm-up measurements after irradiation reveal higher temperature pinnings which all show no dose shift as reported for substages of the stage I in the electrical resistivity measurements after low-temperature electron irradiation, suggesting that these pinnings are due to SIA's released from traps. After the present results, one can Say that the migration temperature of free SIA's in the refractory BCC metals is, in general, very low as below 1.5 K in W and below 6 K in Nb and Ta with the exception of about 40 K in Mo.
© EDP Sciences 1996