This study reports the magnetoelectric (ME) response of lead-free particulate composites given as (1-x)[0.948 K0.5Na 0.5NbO3-0.052 LiSbO3]-xNi0.8Zn 0.2Fe2O4 (KNNLS-NZF) and bimorph laminates given as KNNLS-NZF/Ni/KNNLS-NZF. The particulate ME composites were found to exhibit island-matrix microstructure as confirmed by scanning electron microscopy and elemental mapping. Detailed investigations were conducted on optimization of the magnitude of magnetic and piezoelectric properties by varying the sintering condition and NZF mole fraction. It was found that longitudinal piezoelectric strain coefficient d33 and electromechanical coupling factor kp decreased with increasing NZF concentration. On the other hand, the magnitude of saturation magnetization Ms, remnant magnetization Mr, magnetic permeability μ, and magnetostriction λ was found to increase with increasing NZF fraction. The composition 0.7 KNNLS-0.3 NZF sintered at 1060°C was found to exhibit d33 of 73 pC/N, Ms of 19 emu/g, and maximum ME coefficient αE of 20.14 mV/cm·Oe under Hac=1 Oe at 1 kHz. The bimorph laminates were fabricated by embedding Ni plate between (1-x)KNNLS-xNZF disks with varying electrical connections to achieve radial and bending modes. The radial mode laminates were found to exhibit typical ME response without any self-bias effect with maximum αE of 261.3 mV/cm·Oe and high DC magnetic field sensitivity of 1 μT at 1 kHz. The bending mode laminates were found to exhibit self-biased ME response whose magnitude and shape was dependent upon the NZF concentration.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry