Sea urchin-like Ni encapsulated with BaTiO3 to form multiferroic core-shell structures for room temperature magnetoelectric sensors

Abstract

Since core-shell structures are known to have a high surface area to volume ratio, they are preferred for next-generation memory device applications that require effective strain transfer at the ferroic interface. The present investigation reports the encapsulation of sea urchin-like Ni nanoparticles using BaTiO3 nanoparticles to realize room temperature ME coupled Ni@BaTiO3 system. The magnetic, electric and magnetoelectric properties of Ni nanoparticles partially coated with BaTiO3 provide enough evidence for the existence of ME coupling between Ni and BaTiO3 at their interface. Additionally, we have observed an exchange bias shift upon field cooling, which confirms the presence of the Ni-NiO-BaTiO3 interface in the Ni@BaTiO3 core-shell. The obtained magnetoelectric coupling coefficient of Ni@BaTiO3 composite is 225 µV cm−1 Oe−1. The present study reveals that chemically derived sea urchin-like Ni@BaTiO3 core-shell architecture can be a promising way to design strongly coupled multiferroic memory devices and sensors.