A ferroelectric device, for instance, a metal-ferroelectric-metal (MFM) capacitor, a ferroelectric random access memory (Fe-RAM), or a ferroelectric field effect transistor (FeFET), is provided. In one aspect, the ferroelectric device is based on hafnium zirconate (HZO). The ferroelectric device can include a first electrode and a second electrode, and a doped HZO layer, which is arranged between the first electrode and the second electrode. The doped HZO layer can include a ferroelectric layer and at least two non-zero remnant polarization charge states. The doped HZO layer can be doped with at least two different elements selected from the lanthanide series, or with a combination of at least one element selected from the lanthanide series and at least one rare earth element.