Overlap of the intrinsic and extrinsic magnetoelectric effects in BiFeO_3-PbTiO_3 compounds: Potentialities for magnetic-sensing applications

摘要

The potentialities of BiFeO_3-PbTiO_3 multiferroic compounds for magnetic-field sensing applications is investigated by characterizing the dynamical magnetoelectric response of La doped (0.6)BiFeO_3-(0.4)PbTiO_3 piezoceramics. The results are compared with those obtained in Nb doped (1 wt. %) PbZr_(0.53)Ti_(0.47)O_3 (PZT-5A) piezoceramics and the observed non-linearity of the oscillating voltage response of (0.6)BiFeO_3-(0.4)PbTiO_3 piezoceramics is attributed to the overlapping of the intrinsic and extrinsic magnetoelectric effects that were successfully decoupled by analyzing the in-phase and out-of-phase voltage components relative to applied oscillating magnetic field. For an alternating cosine-like magnetic field of 0.32 Oe, at the piezoelectric resonance frequency (184.2 kHz), the alternating voltage response decreases from 7.77 mV, at -10 kOe, to 2.71 mV, at 1.8 kOe, to subsequently increases until 5.97 mV at 10 kOe. This non-linear voltage response, which can be easily converted into a linear signal by using the phase difference, can be used for static magnetic field sensing in a wide range of magnetic fields.