For authors
Submission status

Archive (English)
   Volumes 41-62
   Volumes 1-20
   Volumes 21-40
      Volume 40
      Volume 39
      Volume 38
      Volume 37
      Volume 36
      Volume 35
      Volume 34
      Volume 33
      Volume 32
      Volume 31
      Volume 30
      Volume 29
      Volume 28
      Volume 27
      Volume 26
      Volume 25
      Volume 24
      Volume 23
      Volume 22
      Volume 21
VOLUME 33 | ISSUE 6 | PAGE 326
Diffusion in two-dimensional crystals
In experiments on the diffusion of a submonolayer barium film on the Mo(l 10) face, Vedula et al.l'2 found that the diffusion coefficient D, the activation energy ea, and the coefficient (D0) of the exponential function are all nonmonotonic functions of the degree of surface coverage θ (the ratio of the actual concentration of adatoms to the concentration in a closely packed monolayer). Earlier studies of structures in this system3 had demonstrated the existence of several commensurable phases at small values of Θ and of an incommensurable phase at θ >0.6. Comparison of structural data with data on diffusion reveals a correlation. In particular, ea and Do have minima at coverages corresponding to the phases C(2 X 6) (0 = 0.8) and C(2 X 2) (0 = 0.6). The activation energy near these minima has clearly defined plateaus in an interval Δ0 ~ 0.1, while D0 increases by a factor of 103 10s in an interval1* Δ0~Ο.1.

Permission given by American Institute of Physics is appreciated.