Lead‐Free Relaxor Ferroelectric Ceramic for High Temperature Self‐Powered X‐Ray Imaging via Phase Boundary Engineering

Self‐powered x‐ray detectors are renowned for compact size, portable design, and energy efficiency, offering significant potential for applications in security checks and industrial testing under extreme conditions. The challenge of designing self‐powered x‐ray detectors operating across a wide temperature range remains a critical hurdle in actual applications. Herein, the x‐ray detection capabilities of a highly polar 0.7BiFeO 3 ‐0.3BaTiO 3 ‐0.005Mn (0.7BF‐0.3BT‐0.005Mn) relaxor ferroelectric ceramic wafer with low‐polarization anisotropic configuration are reported for the first time. This 0.7BF‐0.3BT‐0.005Mn detector achieved a giant sensitivity of 1120 µC Gy air −1 cm −2 (under 70 keV) and a low detection limit of 9 nGy s −1 . It also achieved an ultrahigh self‐powered sensitivity of 688 µC Gy air −1 cm −2 , marking the first reported record‐breaking x‐ray detection performance in a lead‐free ferroelectric ceramic system. Remarkable x‐ray detection performance originates from the high atomic number composition design and the unique low‐anisotropy polarization structure of morphology‐phase boundary (MPB). More importantly, under zero‐bias conditions, the material achieved distortion‐free x‐ray imaging at 150°C, validating its practical application value. This study systematically reveals the intrinsic relationship between local lattice distortion, polarization configuration, and x‐ray detection performance, and provides a clear design concept and structural blueprint for next‐generation radiation detectors with high‐temperature self‐powered.