ST UDY ING OF NICK EL A LLO YS WI T H 1 at .% OF Ge, Zn, In, Zr, A ND Pb BY POSIT RON A NNIHILA TI ON M ETH OD S

The measurements of cold rolled nickel alloys w ith 1 at. % of Ge, Zn, In, Zr, Pb and additional l y T i and Sb by positron lif etime and Doppler broadenin g techni ques have b een done. Mono vacancies w ere a dominati ng typ e of defects in the alloys. The authors of the present pap er connect the di ̃erences betw een the annihi latio n parameters of the investigated samples w ith the existence of the vacancyimpurity atom pairs. A direct prop ortional ity b etw een the vacancy lif etime and the pro duct of vacancyimpuri ty bindin g energy and atomic radius of impurity atom has been found.