High-performance X-ray detection based on intrinsic properties of KLu(WO4)2 and KTb(WO4)2 crystals

Abstract

Developing novel high-performance materials to enhance the precision and reliability of X-ray detection technology is critically important for medical diagnosis, industrial non-destructive testing, and scientific research. The monoclinic potassium double tungstates exhibit significant potential in X-ray detection applications due to their high density, strong X-ray attenuation coefficient, and ordered crystal structure. Herein, we selected and grew KLu(WO₄)₂ and KTb(WO₄)₂ as novel oxide crystals. Due to the unique one-dimensional infinite chains of WO₆ octahedra, which are conducive to efficient transport, these crystals exhibit high mobility lifetime products: 3.1 × 10⁻³ cm² V⁻¹ for KLu(WO₄)₂ and 2.59 × 10⁻³ cm² V⁻¹ for KTb(WO₄)₂. Additionally, benefiting from a pronounced absorption edge at 70 keV where the probability of photoelectric interaction increases sharply, these crystals achieve high sensitivity under 70 keV photon irradiation (525 µC Gy⁻¹ cm⁻² for KLu(WO₄)₂ and 253 µC Gy⁻¹ cm⁻² for KTb(WO₄)₂). The detectors demonstrated low detection limits (34.8 nGy s⁻¹ for KLu(WO₄)₂ and 37.6 nGy s⁻¹ for KTb(WO₄)₂), enabling substantial dose reduction in conventional medical imaging while potentially mitigating associated health risks. These results reveal the application prospects of high-performance X-ray detectors based on KLu(WO₄)₂ and KTb(WO₄)₂ crystals in radiation detection.