Exam1 Fomula Shee - Theoretical Density = nA/Vc N A n =...

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FORMULAE for Exam -1 EMA3010 J= flux ; D = Diffusion coefficient, t = time x = distance Fick’s 1st Law J= -D dC/dx Fick’s 2 nd Law dC/dt= D d 2 C/dx 2 Diffusion Coefficient D = D o exp (-Q/RT) ; Q =activation energy, T= temperature, R = gas constant Concentration versus time for error function solution = (C-Co)/(Cs-Co) = 1 – erf (x/2(Dt) 0.5 ) Co = back ground conc. ; Cs = surface concentration Erf(0) = 0.; erf(0.5) = 0.5; erf(1.0) = 0.84; erf(2.0)= 0.9953
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Unformatted text preview: Theoretical Density = nA/Vc N A n = atoms/cell, A= atomic weight; Vc = volume of unit cell N A = Avagadross number d hkl = a/ (h 2 +k 2 +l 2 ) Bragg Diffraction : n = 2 d hkl sin = Diffraction angle; n= integer ; = wavelength N v = N exp (-Q/RT) [N v = vacancy concentration , N = total number of sites; Q =activation energy, T= temperature, R = gas constant]...
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