Multiphase Transition toward Colorless Bismuth-Germanate Scintillating Glass and Fiber for Radiation Detection.

The applications of scintillating fiber in high-resolution medical imaging, remote radiation monitoring, and microbeam radiation therapy have raised a growing demand of bismuth-germanate (BGO) glass fiber. However, the task of construction of colorless BGO glass fiber has been met with limited success. Here, we present a renewable process that can help to achieve BGO scintillating fiber, based on glass relaxation and crystallization mediated dissolution of unexpected Bi center. The experimental results indicate that the strategy can improve the optical transmittance up to more than 73.17% at 483 nm, which is ∼6.28 times higher than that of the conventional material. Importantly, the obtained nanostructured BGO exhibits bright visible luminescence under excitation with X-ray. Furthermore, it can host various types of rare-earth dopants, and the radiation-induced luminescence can be tuned in a wide waveband region from visible to infrared waveband. In addition, colorless BGO fiber with bright emission is also successfully constructed, and the radiation probing test demonstrates the achievement of ∼19.48 times improvement in the detection sensitivity. Our results highlight the approach based on the dynamic glass relaxation may provide new opportunities for construction of scintillating glass fiber and compact radiation fiber detector.