Effect of Holmium substitution on magnetic, dielectric, and magnetodielectric properties of polycrystalline KBiFe2O5

Abstract

Dielectric, structural, magnetic, and magnetodielectric (MD) properties of polycrystalline KBi1-xHoxFe2O5 (x=0, 0.05, 0.1 and 0.15) prepared by solid-state reaction route is investigated. The magnetization of Ho-substituted KBi0.85Ho0.15Fe2O5 shows a maximum enhancement in its magnetic properties. The remanent magnetization (MR) is increased by ∼8 × 103 times. Moreover, the saturation magnetization (MS) is increased by ∼300 times, whereas a 90% drop in the coercive field (HC) is detected. Temperature-dependent dielectric and magnetic study of KBiFe2O5 (KBFO) exhibit two transitions. The ferroelectric transition (TC) at ∼ 508 °C and antiferromagnetic transition (TN) at ∼ 280 °C. TC is reported to shift to ∼500 °C for the highest Ho doped KBFO. Magnetic field-dependent switchable MD hysteresis of KBi0.95Ho0.05Fe2O5 shows a maximum MD coupling of -0.25%. It resembles field-dependent grain capacitance with a maximum value of -2.4% magnetic grain capacitance. The Ho substitution facilitates the conduction process with large-polaron hopping induced by translation motion. In conclusion, the rare earth (Ho) substituted KBFO plays a vital role in showing anomalous MD coupling with enhanced magnetization and reduced transition temperatures (TN and TC).