bigstar25 - Thanks heaps for your help and although you may be right about the use of that formula for extrin. and intrin. we (being first years) were only told to use it for intrin. NOT extrin. so I and the other students I checked with just used the conductivity formula with hole mobility...
I have exactly the same question and I tried to solve it using simultaneous equations you suggested, but I ended up with a stupid quadratic and two impossible answers - that the value of n is 0 or negative...
Also, we haven't been taught most of the formulas you're using so I'm pretty sure we...
I'm assuming the vacancy densities would mean number of vacancies per number of atomic sites... And the ratio then is a comparison between the two densities at those two temperatures? Number of vacancies is usually just a number of how many there are at a given temperature and input energy...
Ok first of all, the lattice constant (a) is just the length of one side of the unit cell - not the total number of atomic sites (N) BUT you're right to think the two are related.
Number of atomic sites is given with:
N = NAp/AFe
Where AFe is the atomic mass of iron: 55.845g
NA is...
The formula is: Nv= Ne(-Q/kT) (usually written as exp(-Q/kT)
where:
Nv is the number of vacancies
N is the total number of atomic sites (which would relate to the crystal structure and lattice constant)
e is the natural exponential 2.71828 etc
Q is the energy required for vacancy...
Hey, I had a similar question just recently - actually... it was the same except 5 instead of 6 :P
Anyway, I did pretty much the same as you but once I got Nv = Nexp(-Q/kT) and 6Nv = Nexp(-Q/kT) I did some funky stuff with natural log. Firstly, exp is ex (or an exponent x with base e) so you...