Second-order transition S.J.T.U. Phase Transformation and Applications First derivatives of G with respect to T and p are continuous and the second derivatives of G with respect to T and P are discontinuous S=SB S=S(T,p) dS dT dp T dS = dp SJTU Thermodynamics of Materials Spring2006©X.J.Jin Lecture 9 Chemical equilibrium llPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 9 Chemical equilibrium II Second-order transition First derivatives of G with respect to T and p are continuous and the second derivatives of G with respect to T and P are discontinuous BA = SS = ( , pTSS ) dp p S dT T S Sd p T ⎟⎟⎠⎞ ⎜⎜⎝⎛ ∂∂ ⎟ + ⎠⎞ ⎜⎝⎛ ∂∂ = dp TV dT TC Sd p p ⎟⎠⎞ ⎜⎝⎛ ∂∂ −= p p TS TC ⎟⎠⎞ ⎜⎝⎛ ∂∂ =