Abstract:
Magnetoelectric composite materials consisting of coupled magnetic and ferroelectric phases open
doors to exciting applications like electrically controlled magnetic sensors and memories. In this
direction, we report the first-time observation of the exchange-spring mechanism in nickel–barium
titanate magnetoelectric composite systems. The low field DC magnetization measurements of the
Ni–BaTiO3 composite systems reveal an anomalous magnetic behaviour indicating the presence of a
Griffiths-like phase. The exchange bias loop shift observed in the Ni–BaTiO3 systems confirms the
formation of antiferromagnetic NiO. The structural transitions of BaTiO3 visible in the magnetic data
implicate magnetoelectric coupling between Ni and BaTiO3. The maximum value of the magnetoelectric
coupling coefficients observed for the Ni–BaTiO3 0–3 composites is 18.53 mV cm Oe1
, and for the
composites with 1–3 connectivity it is 10.91 mV cm Oe1
; both values are higher than the reported
values of Ni–BaTiO3 particulate composites. In addition to this, the magnetoelectric coupling
coefficients of the Ni–BaTiO3 composites with 1–3 connectivity show an increasing trend towards the
BaTiO3 rich composite.
