Enhancement of Curie temperature of barium hexaferrite by dense electronic excitations

Curie temperature of polycrystalline barium hexaferrite (BaFe12O19), prepared by conventional solid state technique, is anomalously and significantly enhanced (by nearly 15%) by energetic heavy ion irradiation (150 MeV, Ag12+) at ambient temperature due to dense electronic excitations Moderate fluence (1 × 1012 ions/cm2) induces structural defects giving rise to above enhancement. As established by X-ray diffraction, scanning electron microscopy and Raman studies, higher fluence (1 × 1013 ions/cm2) has structurally transformed the sample to amorphous phase with marginal change in magnetization and Curie temperature.