Enhanced magnetoelectric effect in (1 - X) Pb(Zr_0.52Ti _0.48)O₃-x NiFe_1.9Mn_0.1O₄ particulate composites - Electrical and magnetic properties

In this paper, the ferroelectric, ferromagnetic and magnetoelectric properties of lead zirconate titanate and nickel ferrite composite (1 - x) Pb(Zr 0.52 Ti 0.48 )O 3 -x NiFe 1.9 Mn 0.1 O 4 (PZT-NFM, x = 0.03, 0.05, 0.1) are reported. The magnetoelectric composites were fabricated using the process based on controlled precipitation route, a combination of conventional mixed oxide sintering and thermal treatment. The thermal treatment constituted of annealing at high temperature close to the calcination temperature followed by aging at lower temperatures. The phase diagram for the system PZT-NFM was not investigated in this study but an estimation of the phase fields for the PZT-rich end was conducted using the X-ray diffraction. Microstructure of the fabricated samples was analyzed using the X-ray mapping in SEM. The density of the composites sintered in the temperature range of 1100-1125°C was in the range of 7.2-7.8 gm/cm 3 , increasing with NFM content. The magnitude of piezoelectric constant (d 33 ) and the piezoelectric voltage constant decreased with increasing NFM content. The magnitude of magnetoelectric (ME) voltage coefficient (dE/dH) increased with increasing NFM content. The 0.9 PZT-0.1 NFM samples sintered at 1125°C exhibited ME coefficient of 78 mV/cm Oe. This magnitude increased to 105 mV/cm Oe after the thermal treatment (annealing and aging). It is expected that this enhancement is due to the change in the size of the NFM phase.