The kinetics of the interdiffusion of Co adatoms on a (111) surface were studied, by means of Auger electron spectroscopy at various temperatures, for Co coverages which were near to 1 monolayer. It was found that, after annealing, the Co concentration decreased markedly before approaching a constant value. It was noted that Co-Pt alloy formation was confined to a few uppermost layers. The activation energy and pre-exponential factor were obtained from an Arrhenius plot, and were equal to 0.90eV and 6.6 x 10-11cm2/s. These values were independent of the coverage in this ultra-thin system. After annealing 1-monolayer Co ultra-thin films on the (111) surface at 600K, Co atoms diffused into only the first 2 monolayers. Both the uppermost and second layers contained 50%Co.

J.S.Tsay, C.S.Shern: Journal of Applied Physics, 1996, 80[7], 3777-81

 

Table 108

Diffusion of H in Pt

 

Temperature (C)

D (m2/s)

558

1.26 x 10-8

606

1.50 x 10-8

666

1.92 x 10-8

726

2.45 x 10-8

748

2.33 x 10-8

751

3.25 x 10-8

772

2.80 x 10-8

797

3.40 x 10-8

804

2.93 x 10-8

831

3.12 x 10-8

885

3.66 x 10-8

896

4.20 x 10-8

936

4.05 x 10-8

872

3.63 x 10-8

767

2.80 x 10-8

754

3.30 x 10-8

735

2.75 x 10-8

713

2.45 x 10-8

679

2.32 x 10-8

630

1.93 x 10-8