A diffusive memristor device and an electronic device for emulating a biological synapse are disclosed. The diffusive memristor device includes a bottom electrode, a top electrode formed opposite the bottom electrode, and a dielectric layer disposed between the top electrode and the bottom electrode. The dielectric layer comprises silver doped silicon oxynitride (SiOxNy:Ag). In an alternate implementation, the dielectric layer comprises silver doped silicon oxide (Ag:SiO2). An electronic synapse emulation device is also disclosed. The synapse emulation device includes a diffusive memristor device, a drift memristor device connected in series with the diffusive memristor device, a first voltage pulse generator connected to the diffusive memristor device, and a second voltage pulse generator connected to the drift memristor device. Application of a signal from one of the first voltage pulse generator or the second voltage pulse generator allows the synapse emulation device to exhibit long-term plasticity.