T. Kizuka et al., CRITICAL GRAIN-SIZE FOR STRUCTURAL TRANSFORMATION IN VACUUM-DEPOSITEDMOLYBDENUM FILMS, Surface review and letters, 3(1), 1996, pp. 1181-1185
Nanometer-grained polycrystalline films were prepared by vacuum deposi
tion of molybdenum (Mo) by using electron-beam heating. The structure
and composition of the grains were analyzed by high-resolution electro
n microscopy and Auger electron spectroscopy, respectively. The concen
tration of carbon in the films was measured in relation to reduction o
f the grain size to nanometer scale. The grains had a bcc structure wh
en the grain size was larger than 4 nm. On the other hand, the grains
smaller than 4 nm for films had a fee structure. Large amount of carbo
n was included in the grains with the fee structure in comparison with
the grains of bcc structure, although amount of other impurities such
as nitrogen and oxygen was similar in both grains. It was found that
the structure was transformed from bcc to fee below the critical grain
size, 4 nm, and the grains with the fee structure were cubic Mo-C.