Final Exam Review

# Final Exam Review - Semiconductors – σ = n i q(mu n mu p...

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Final Exam Review 50 definitions 2 pts each 6 problems 50 pts each Unit 1 mostly definitions BCC 2 atoms per unit cell CN = 8 CN means number of nearest neighbors Close packed directions – <111> Also the direction of dislocation 4R = sqrt(3)a APF = 2*4/3piR 3 /(4R/sqrt(3)) 3 = .68 Density = 2(A.W./n a )/a 3 FCC 4 atoms per unit cell CN = 12 Close packed directions – <110> 4R = sqrt(2)a APF = 4*4/3piR 3 /a 3 = .74 Unit 2 – Properties of materials Conductors – V = IR Rho = RA/l Conductivity = 1/rho = nqu R = pl/A metallic materials – conductors thermal vibrations T – xaxis Rho – y axis Positive sloped line Starts at P r – defects Unit 3 Metallic conductors P = P 0 (1+alphaT) Y = mx + b – b is P

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Unformatted text preview: Semiconductors – σ = n i q(mu n + mu p ) – only for intrinsic semiconductors extrinsic – column V n-type column III p-type σ = nqu Diffusion to permeate dopants Ficks second law to find n Assuming complete ionization Stress and strain Stress - σ = F/A o strain - Σ = l – l o /l o = dl/l o F vs dl looks like stress – strain Slope = modulus of elasticity = stress/strain = σ/ Σ GPa = 10 3 MPa Specific strength – UTMS/density Fracture toughness – K IC = Y σsqrt(pi*a) Surface crack is 1a Diffusion Error function problem D = D o e-Q/RT NO LEVER LAW Phase change question Phase diagrams...
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Final Exam Review - Semiconductors – σ = n i q(mu n mu p...

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