A single crystal of YALO₃: Ce³⁺ as a fast scintillator in SEM

Abstract

Abstract A new single‐crystal scintillator intended for applications in a scanning electron microscope (SEM) is presented. It is a single‐crystal disc of yttrium aluminium perovskite activated by trivalent cerium free of traces of Fe ions. The single crystals of YAlO 3 : Ce 3+ (YAP: Ce 3+ ) were prepared by the Czochralski method in a reducing atmosphere of Ar and H 2 with an excess amount of Y 3+ ions. Effective methods of purification and purity control of the raw material are described. The highest achievable concentration of Ce 3+ ions in as grown crystals amounted to 0.3 wt%, concentration in the melt was 8–9 times higher. The best properties were found with samples of the maximum possible concentration of Ce 3+ . Compared with the previous aluminate Y 3 Al 5 O 12 : Ce 3+ (YAG: Ce 3+ ) these samples showed higher efficiency, a shorter decay time of luminescence (40 ns) and an emission band in a more advantageous spectral region (378 nm). Because of high resistance to radiation damage, high chemical resistance and applicability to ultra‐high vacuum it is also suitable for detection of other kinds of ionizing radiation.