Wang, BY (reprint author), Chinese Acad Sci, Inst High Energy Phys, Key Lab Nucl Anal Tech, Beijing 100049, Peoples R China.
The point defects of B2-type intermetallic compound Ni-Al have been investigated as a function of different Ni compositions ranging from 47 to 55 at.% by means of positron lifetime and coincidence Doppler-broadening (CDB) measurements. The position lifetime of the annealed samples, expressed by single-component lifetime of tau = 170-180 ps, indicates positron saturation trapping at single vacancies in Ni-Al samples. The CDB measurements have been applied to identify these vacancy-type defects formed on the Ni sublattice in the B2-phase Ni-Al alloys. (C) 2007 Elsevier B.V. All rights reserved.