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Unformatted text preview: ion? c) If D = 0.27exp(‐17,400/T) cm2/s, what temperature increase is required to get 0.45% C at a depth of 0.1cm in the same time as 0.05cm was attained at 930oC. Q3: We know that when D > 0, matters diffuse from locations with high concentration to locations with lower concentration. What happens if D<0? Please also provide an example. Q4: a) Please provide a brief explanation of what is surface diffusion. b) Suggest an experimental technique suitable for studying surface diffusion. c) Which of the two is faster? Surface diffusion or bulk diffusion? Why? Q5: For diffusion of 1017 198 Au radiotracer atoms into 197 Au at 600 oC by a diffusion length λD = 0.1 μ m , calculate the drift velocity v, mobility M and driving force F at λ = 1 2 λD ....
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- Spring '09