Ultrawide bandgap Sm-based zirconate transparent dielectrics: Phase evolution-driven optical and dielectric enhancement

Ultrawide bandgap (UWBG) materials are recognized for their high thermal stability, high breakdown voltages, and transparency, which make them ideal for a variety of optical and electronic devices. This study investigates the phase evolution and its effects on the optical and dielectric properties of samarium-based zirconate (Sm₂Zr₂O₇) transparent dielectric ceramics, with a focus on their potential for advanced optoelectronic applications. The A₂B₂O₇ structure of samarium-based zirconates provides key advantages, including high mechanical stability, tunable optical transparency, and enhanced dielectric performance. Through systematic experimental analysis, we explore how A-site substitution induces phase evolution from defective fluorite to pyrochlore and influences both the optical transparency and dielectric properties. The bandgap of prepared ceramic achieved up to 4.4 eV with high dielectric constant (25.5) and low dielectric loss (0.4). The results demonstrate that controlled phase changes significantly enhance the material's dielectric characteristics, making samarium-based zirconates suitable for applications in transparent capacitors and radiation sensors. Our finding provides valuable insights into the design and optimization of bulk transparent UWBG materials, promoting their use in next-generation optoelectronic devices.