ELECTRON SCATTERING & RESISTIVITY OF METALS ppt.
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 seminar surveyer Active In SP Posts: 3,541 Joined: Sep 2010 04-01-2011, 03:39 PM   e- scattering.pptx (Size: 107.66 KB / Downloads: 91) CONDUCTIVITY σ ,FERMI LEVEL , MEAN FREE PATH & RELAXATION TIME ť FOR TYPICAL MONO-VALENT METALS IS SHOWN IN TABLE The conductivity σ may be obtained experimentally . Further we can get ť by using eqn given below σ = ( n*Qe2 *ť )/me ---------(1) but ť obtained may not be accurate but we will get an idea of magnitude of ť . In a monovalent metal no of free e- /m3 is equals the no of atoms /m3 . From table we find that relaxation time T is of the order of 10-14 sec .Thus we can say that T is extremely small for monovalent metals. from eqn. given below we can calculate mean free path λ- λ = Vx * ťc ----------(2) The relaxation time ť for metals refers to e- with Fermi velocity Vf .For usual values of temp. T , it may be shown that the scattering in these monovalent metals is isotropic . Then, ť=tc & λ = Vx * ťc .The values of man free path at 0 0c are several hundred angstroms. We find from the graph shown that as we goes on reducing the temp of a metal then it’s resistivity also decreases & vice versa but assume a constant value of temp. below 6 K. In general, the resistivity of a perfect, pure single crystal of a metal approaches to zero as temp. T approaches zero. This signifies that at very low temp. the mean free path λ assumes microscopic values .This concludes that the earlier discussions are not individual ion cores.
 Guest Thinking To Register 25-10-2012, 03:26 AM why do we call it electron scattering, in fact i want to know more about it in an atom ?? please answer it for me i will be grateful to u
 seminar tips Super Moderator Posts: 8,857 Joined: Oct 2012 25-10-2012, 10:47 AM to get information about the topic "ELECTRON SCATTERING & RESISTIVITY OF METALS"full report refer the link bellow http://topicideas.org/how-to-electron-sc...metals-ppt