C. Buhrer et al., POSITRON-ANNIHILATION IN SOLID, LIQUID AND UNDERCOOLED MELTS OF CO80PD20, Applied physics A: Materials science & processing, 63(2), 1996, pp. 191-194
Positron annihilation measurements have been performed in solid, liqui
d and undercooled Co80Pd20 alloy using electromagnetic levitation as c
ontainerless processing method. The formation enthalpy for a single va
cancy is H-1v = (1.7 +/- 0.1) eV. In the melt, the thermal expansion c
ontinues linear in the undercooled phase and is larger than that of th
e solid alloy. The mean free volume in the liquid phase is slightly la
rger than the volume of a single vacancy. At the Curie temperatures of
both solid and liquid phase, the S-parameter indicates no effect on t
he atomic structure. Different H-2 concentrations in the processing ga
s atmosphere have no detectable influence on the data.