Based on precursor powders with a size of 200-300 nm prepared by the low-temperature solid-state reaction method, phase-pure YMnO₃ ceramics are fabricated using spark plasma sintering (SPS). X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal that the high-purity YMnO₃ ceramics can be prepared by SPS at 1000 °C for 5 minutes with annealing at 800 °C for 2 h. The relative density of the sample is as high as 97%, which is much higher than those of the samples sintered by other methods. The present dielectric and magnetic properties are much better than those of the samples fabricated by conventional methods and SPS with ball-milling precursors, and the ferroelectric loops at room temperature can be detected. These findings indicate that the YMnO₃ ceramics prepared by the low temperature solid reaction method and SPS possess excellent dielectric lossy ferroelectric properties at room temperature, and magnetic properties at low temperature (10 K), making them suitable for potential multiferroic applications.
Keywords: dielectric properties; ferroelectric properties; low-temperature solid-state reaction; magnetic properties; multiferroic materials; spark plasma sintering.