Measurement of surface diffusion coefficients in air of columnar structured platinum near room temperature

The surface self-diffusion coefficients, DS, of columnar structured Pt were measured in air following the decrease with time of the roughness factor obtained by means of electrochemical techniques. From DS values in a narrow temperature range (20–60°C), the activation enthalpy for the surface self-diffusion process and the pre-exponential factor D0 have been calculated as 47.5 kJ mol−1 and 3.3×10−11 cm2 s−1, respectively. The low values of DS are the consequence of low D0, since the activation enthalpy is lower than that necessary to induce surface diffusion at temperatures close to the melting point of Pt.