Development of multiferroic CFO:BTO core-shell nanocomposite inks for inkjet printing

Cobalt ferrite (CFO), barium titanate (BTO) core-shell nanoparticles (CFO:BTO NPs) exhibit multiferroic properties through the magnetoelectric effect. Inkjet printing is a direct-write, additive manufacturing technique for fabrication of electronic components and devices. Hansen Solubility Parameters (HSP) are a practical tool to understand solution and dispersion behavior of materials in a mixture. This work applies HSP analysis to improve CFO:BTO NPs synthesis and guide the ink formulation process. The estimated HSP values for CFO:BTO core-shell NPs (dD = 15.5, dP = 11.9, dH = 23, r = 4.6), CFO (dD = 15.9, dP = 10.6, dH = 22.5, r = 4.9), and BTO (dD = 16.6, dP = 9.7, dH = 15.4, r = 5.8) are analyzed. Limits and considerations of the HSP are discussed and results are combined with solvent thermal and fluid properties to develop ink formulations for multi-functional, multi-material inkjet printing applications.