Abstract: Multilayer structure, used especially as a material of high relative permittivity, characterized in that it comprises a plurality of separate layers, each having a thickness of less than 500 Å. Some of those layers are based on aluminium, hafnium and oxygen and especially based on hafnium dioxide (HfO2) and on alumina (Al2O3). In practice, the hafnium dioxide and alumina layers form alloys of formula HfxAlyOz. Advantageously, the stoichiometry of the HfxAlyOz varies from one layer to another. Some of the layers containing HfxAlyOz alloys, or some of the layers between those containing HfxAlyOz alloys, also include a lanthanide element.