INVESTIGATION OF MULTIFERROIC HETEROSTRUCTURES FOR ELECTRONIC DEVICE APPLICATIONS

Abstract

The multiferroic materials combine at least two ferroic orders from ferroelectricity, ferromagnetism, and ferroelasticity. These materials are rich in physics as well as real-time device applications. The multiferroic orders can exist in single-phase or heterostructure configurations. Many fascinating phenomena can be discovered by fabricating multiferroic heterostructures. The ferromagnetic shape memory alloys (FSMAs) belong to a class of multiferroics, which exhibits martensite transformation and ferromagnetism. FSMAs show the unique coupling between mechanical and magnetic orders. The martensite transformation is a first-order structural transformation from a high-temperature phase to a low-temperature phase. The Ni-Mn-In belongs to FSMA material that exhibits metallic behavior and large magnetic field-induced strain. These exceptional and unique characteristics can be further explored by introducing the Ni-Mn-In layer in magnetoelectric and resistive switching-based devices. In this work, Ni-Mn-In/PLZT and Ni-Mn-In/MoS2 heterostructures have been fabricated for electronic device applications. The magnetoelectric heterostructures consist of ferroelectric and ferromagnetic materials. The selection of constituent ferromagnetic and ferroelectric layers is vital to enhance magnetoelectric coupling. The FMSA (especially Ni-Mn-In) is an excellent choice as a ferromagnetic layer due to its unique martensite transformation, large magnetostriction, and fast frequency response compared to other leading ferromagnetic materials. On the other hand, PLZT exhibits comparatively excellent piezoelectric and electromechanical coupling coefficients among the ferroelectric materials. Therefore, Ni-Mn-In/PLZT based multiferroic heterostructure has been fabricated. The magnetic field sensing and infrared detection characteristics of Ni-Mn- In/PLZT heterostructures have been performed.