Improved magnetoelectric properties of piezoelectric-magnetostrictive nanocomposites synthesized using high-pressure compaction technique

The high-compaction sintering technique of PZT-NFO (piezoelectric nickel ferrite) nano core shell structure to form a dense magnetoelectric (ME) particulate composite, was investigated. The synthesis of nickel ferrite nanoparticles was performed by standard airless chemical synthesis technique in a nitrogen atmosphere. A mixture of 1 mmol of Ni-II (acetyl acetonate) and 2 mmol of 1,2-hexadecanediol (HDD) was added to a 125-mL European flask containing a magnetic stir bar. Benzyl ether was then transferred to the flask and the contents were stirred while purging with N₂ for 20 mill at room temperature. Pellets of three different schemes were pressed in a 0.25-in, die under hydraulic pressure of 2 kpsi followed by cold isostatic pressure of 30 kpsi. The grain size was found to reduce with increasing NFO concentration in the composite. It was also observed that composites corresponding to formulation 1:1 have the highest magnetoelectric coefficient, which could be related to higher resistivity and dense microstructure.