A nanofilm method has been developed to study the formation of low-energy interfaces by the rotation of nanograins. Ion-beam sputtering was used to prepare very thin epitaxial NiO nanofilms on the (100), (110), (111), and (112) surfaces of NaCl single crystals. When two different NiO nanofilms were overlapped at different angles and annealed at 300 °C, the nanograins were found to rotate until a stable interface was reached. The stable interfaces were analyzed by transmission electron microscopy. Several previously unreported interfaces were found that belong to the asymmetric [110] tilt boundaries on different low-index planes. The orientation relationships and the structures of the interfaces were analyzed.