Fig. 3
a Reciprocal space and b XRD pattern of a poly-domain Pb(Zr0.2Ti0.8)O3 thin film on MgO. The c domains give rise to one out-of-plane lattice parameter and so do the a domains, there are therefore two diffraction peaks. The misorientation between the two domain types is illustrated in (c). The angle between the normals is sometimes reported as being π/2−2arctg (a/c) (e.g., in [71]). Though giving the exact same value for Δω, this expression takes the normal to the a domains as the reference, which seems less appropriate. The resulting difference in incidence (ω) angle between the two domain types as well as the separation in 2Θ is illustrated by the reciprocal space map on (d)