Effects of post-annealing temperature and micropillar shape on physical properties of micropillar-type multiferroic composite thin films

Microplate (MP) and microrod (MR)-type CoFe2O4/(Bi3.25Nd0.65Eu0.10)Ti3O12 composite thin films were fabricated by a combination of reactive ion etching and metalorganic chemical vapor deposition. The effects of post-annealing temperature on the structural, magnetic, electrical, and magnetoelectric (ME) properties of the films were investigated. Based on the results, the optimal ferroelectric pillar structure to obtain a large ME voltage coefficient (alpha ME ) was determined. The electrical insulation properties for the films improved with increasing post-annealing temperature. On the other hand, magnetic and ferroelectric properties were degraded at high-temperature. Judging from the structural, magnetic, electric, and ME properties, the optimum post-annealing temperature was 700 degrees C. The shape of the ferroelectric layer had a significant influence on the ferroelectric properties and consequently on alpha ME . The MR shape exhibited a smaller clamping effect than the MP shape, producing a greater ME effect. The alpha ME for the MR-type film post-annealed at 700 degrees C was 5.5 mV cm-1 Oe-1.

Automated summary

Microplate (MP) and microrod (MR)-type CoFe2O4/(Bi3.25Nd0.65Eu0.10)Ti3O12 composite thin films were fabricated using a combination of reactive ion etching and metalorganic chemical vapor deposition. The optimal post-annealing temperature of 700 degrees C was found to improve the magnetoelectric (ME) properties, with MR shape showing a greater ME effect compared to MP shape. The electrical insulation properties of the films improved with increasing post-annealing temperature, while high-temperature caused degradation in magnetic and ferroelectric properties.