A holographic approach to point defect structure determination in inorganic crystals: Er-doped Sc₂O₃

A holographic approach to the analysis of a Bragg scattering pattern has been described by Szöke [Acta Cryst. (1993), A49, 853-866]. The combination of crystallographic procedures and holographic interpretation allows reconstruction of an unknown part of the crystalline structure model-free if the other part of the structure is known. By introducing the concept of an average crystal, this approach is extended to point defect structures in inorganic crystals. In this case, the host lattice is well known while the defect structure is regarded as the unknown part. To demonstrate the feasibility of this approach, an Sc₂O₃ sample doped with Er at low concentration has been studied. An additional electron density has been observed, which can be interpreted as an interstitial Er position.