Structural characterization and multiferroic properties of hexagonal nano-sized YMnO3 developed by a low temperature precursor route

Abstract

Multiferroic YMnO₃ nanoparticles with a narrow size distribution and high specific surface area (304 m² g⁻¹) were synthesized using a low temperature polymeric citrate precursor route for the first time. The crystal structure of the monophasic hexagonal YMnO₃ nanoparticles was estimated by powder X-ray diffraction studies. The transmission and scanning electron microscopic studies revealed nearly hexagonal nanostructures with an average grain size of ∼48 nm. The optical band gap was found to be 3.7 eV and photoluminescence studies also suggest the wide band gap semiconducting nature of YMnO₃. DC-magnetization studies of YMnO₃ nanoparticles show ferromagnetic hysteresis with saturation magnetization of 21.19 emu g⁻¹. The appearance of a room temperature ferroelectric loop at 50 kHz has been observed for the first time with an improved remanent polarization of 0.0084 μC cm⁻². The dielectric properties on sintered disks were also investigated as a function of frequency and temperature.