A process for fabricating an antiferromagnetic layer includes depositing on a substrate a first layer with a sufficient thickness to establish a specific magnetic order from among one of the following orders, ferrimagnetic, ferromagnetic, paramagnetic, diamagnetic; after establishing the ferrimagnetic, ferromagnetic, paramagnetic or diamagnetic order, applying a magnetic field with sufficient amplitude and duration to shift walls of the magnetic domains of the first layer from a first statistical distribution to a second statistical distribution, the second statistical distribution presenting a minimum magnetic domain size strictly greater than the minimum magnetic domain size of the first statistical distribution and; for a given area, magnetic domains in which the perimeter is greater than that of domains from the first statistical distribution; and depositing on the first layer whose magnetic domain walls have been shifted, a second layer of an antiferromagnetic material in which at least one of the components of material of the first layer may be integrated by diffusion during growth.