A new approach has been developed to investigate the formation and properties of hetero-boundaries in ceramics. Thinned TEM foils, which have been carefully cleaned and annealed to produce a well-defined surface morphology, act as the substrate for the subsequent deposition process. The early stages of the epitactic growth of NiO and Fe2O3 on Al2O3 and of YBa2Cu3O7-partial on MgO are reported. The method has been applied to study the NiO/NiAl2O4/Al2O3 solid-state reaction couple.