Multifunctionality in Electrically Poled PMN–PT/Ni–Mn–In Multiferroic Heterostructure for Flexible Magnetic Field Sensing and Nonvolatile Memory Applications
Diksha Arora, Pradeep Kumar, Davinder Kaur
Abstract
Ever-evolving advances in flexible magnetoelectric (ME) devices are propitious for technical innovations in touchless human–machine interaction, wearable sensors, artificial intelligence, and next-generation memory devices. In this study, a cost-effective and flexible ME heterostructure comprising thin films of 0.67Pb (Mg 1/3 Nb 2/3 )O 3 –0.33PbTiO 3 (PMN–PT) and ferromagnetic shape memory alloy (Ni–Mn–In, FSMA) has been fabricated over flexible stainless steel substrate. The ME coupling characteristics of the flexible PMN–PT/FSMA multiferroic heterostructure have been explored for magnetic sensor and nonvolatile memory applications. The influence of phase fraction, anisotropy, and poling on ME coefficients has been thoroughly studied to obtain the optimum ME coupling. A notable ME coupling coefficient of ∼4.1 V cm –1 Oe – 1 at 250 Oe of H DC has been obtained in electrically poled PMN–PT/FSMA/SS multiferroic heterostructure, making it promising for room-temperature low-field magnetic sensors. The flexible heterostructure possesses noteworthy device sensing parameters, i.e., correlation coefficient ∼0.99945, sensitivity ∼0.72 mV/Oe, inaccuracy ∼1.34% FSO, and hysteresis ∼1.72% FSO. The electric field-controlled switching of ME coefficient observed in PMN–PT/FSMA heterostructure is beneficial for high-density nonvolatile memory devices. The flexible ME heterostructure displays an excellent mechanical endurance of up to 2000 bending cycles. The remarkable response of such flexible ME heterostructures at room temperature makes them promising for flexible magnetic field sensors, nonvolatile memory, spintronics, and multifunctional device applications.