Tunable Magnetoelectric Nonvolatile Memory Devices Based on SmFeO₃/P(VDF-TrFE) Nanocomposite Films

Utilization of magnetoelectric effects in multiferroic materials hold great potential to fabricate nonvolatile memory devices with outstanding characteristics. In particular, organic thin memories are favorable because of their environment friendly nature, mechanical flexibility, and low fabrication cost. In this work, we have demonstrated a room temperature paradigm two level nonvolatile memory operation by exploiting the nonlinear magnetoelectric effects in flexible SmFeO₃/P­(VDF-TrFE) nanocomposite films using organic ferroelectric polymer (P­(VDF-TrFE)) as a host matrix. Strong strain mediated interfacial interactions between ferromagnetic and ferroelectric phases in SmFeO₃/P­(VDF-TrFE) nanocomposite films allow electric field controlled magnetic switching. The maximum magnetoelectric coefficient (α) obtained is 45 mV cm^–1 Oe^1– at <i>H</i>_bias= 1 kOe and 16 mV cm^–1 Oe^1– at <i>H</i>_bias= 0 in electrically poled composite films (30% SmFeO₃). The experiments demonstrate that during seven operative cycles for 1500 s, the applied positive and negative electric fields can repeatedly switch states of α. Binary information is stored by using the states of α, rather than resistance, magnetization, and electric polarization, which is advantageous to overcome the drawback of destructive reading of polarization of ferroelectric random access memory. The magnetoelectric response and the required voltage for switching of α can be tuned by varying the magnetic phase fraction (SmFeO₃ nanoparticles) in nanocomposite films. Hence, the kind of nonvolatile memory using organic, flexible magnetoelectric SmFeO₃/P­(VDF-TrFE) nanocomposite films has excellent practical characteristics, that is, compactness, easy and fast speed reading/writing operation, and reduced power consumption