You cannot measure stress from a diffraction experiment but (try to)
calculate it from the strain which you can measure. Please specify: is it
macro-st.rain (=residual strain --> line shift) on polycrystalline solids or
micro-strain on polycrystalline powders or - solids (--> line broadening), or
both? what is the chemical system (metal, ceramic, polymer), thin films or
bulk? -- A good start wih the fundamentals of macro-stress is the book by
Noyan/Cohen "Residual Stress" (1987). For micro-stress you better go back to
Warren's book "X-ray Diffraction" (1969) which includes a chapter of the
Fourier analysis of size/strain-broadened line profiles (Warren-Averbach
technique).
L. Keller
