Origin of a continuously enlarge memristor effect in Nb inserted into MgB2 multilayer constructed heterojunctions

In this work, a resistive switching memory device, in which niobium (Nb) inserted into magnesium diboride (MgB2) multilayer constructed heterojunctions, was prepared by vacuum sputtering at 400 °C. Furthermore, a continuously enlarge memristor memory effect was observed in Ti/(MgB2/Nb)n/MgB2/Ti (n = 0, 1, 2, 3) devices with the increasing of the inserted Nb layers numbers for the first time. Finally, a model of Schottky barrier based on interfaces of Ti/MgB2 and Nb/MgB2 are used to explain the memory characteristics.