The low-pressure oxidation of the Co(1610) surface has been studied wi
thin the temperature range 25-250-degrees-C using ellipsometry. After
the oxidation high-energy ion scattering, in combination with shadowin
g and blocking, has been performed to obtain values for the absolute o
xygen coverage and the stoichiometry of the oxide. At room temperature
the oxidation virtually stops at a value of the ellipsometric paramet
er deltaDELTA = 2.71-degrees +/- 0.04-degrees, corresponding to an oxy
gen coverage of (4.1 +/- 0.1) x 10(15) oxygen atoms/cm2. At 200 and 25
0-degrees-C the initial oxidation rate appears lower but no saturation
is observed: after a fast initial stage, in which about 7 x 10(15) ox
ygen atoms/cm2 are taken up, the oxidation proceeds with a relatively
tow rate. Low-energy electron diffraction measurements show that no st
ructure is present after room-temperature oxidation, but oxidation at
200 and 250-degrees-C results in a partially ordered oxide. The stoich
iometry of the oxide is found to be Co1.03+/-0.15O.