Improved texture of polycrystalline hexaferrites using gluconic acid dispersant.

In this work, gluconic acid (GA), a low molecular weight, inexpensive and environmentally friendly solvent, was systematically investigated to determine its viability in enhancing the orientation of ferrite particles. Submicron-scale barium hexaferrite (BaM) powders were thoroughly dispersed via sonication for 30 min in various concentrations of GA (0, 2, 2.5, 5, 10, and 25 vol. %) in deionized water. An increase of ~18% in squareness (SQ) and ~69% in energy product ((BH)max) was observed with increase in GA concentration from 0 to 5 vol. %. However, further increase in GA concentration led to a decrease in SQ and (BH)max confirming that the effect of GA stems from an improved viscosity of the dispersant, which balances the freely rotating and stationary particles under dynamic compaction within a magnetic field. [ABSTRACT FROM AUTHOR]