Can any1 help me with this?
Explain why the activation energy of a system can vary depending on:
a. Host species bond type
b. Host crystal structure
c. Diffusing atom size
Explain why the activation energy of a system can vary depending on:
a. Host species bond type
b. Host crystal structure
c. Diffusing atom size
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Are you in MATE 210 at Cal Poly?
I think you just have to look at the relationships in the diffusion coefficient equation.
D=Doexp(-Qd/RT)
As can be seen in the equation, the activation energy Qd is a function of Do which is dependent upon the host species and host crystal structure. As far as atom size I think that can be seen when looking at both mechanisms for diffusion. Only small atoms can use interstitial diffusion and it has a rather low activation energy compared to vacancy diffusion. So a correlation can be drawn that way. Hopefully that helps. That's the best I have.
I think you just have to look at the relationships in the diffusion coefficient equation.
D=Doexp(-Qd/RT)
As can be seen in the equation, the activation energy Qd is a function of Do which is dependent upon the host species and host crystal structure. As far as atom size I think that can be seen when looking at both mechanisms for diffusion. Only small atoms can use interstitial diffusion and it has a rather low activation energy compared to vacancy diffusion. So a correlation can be drawn that way. Hopefully that helps. That's the best I have.