Purification and crystallinity results from LiZnAs and LiZnP semiconductor materials

Nowotny-Juza compounds continue to be explored as candidates for solid-state neutron detectors. Such devices would have greater efficiency, in a compact form, than present day gas-filled ³He and ¹⁰BF₃ detectors. The ⁶Li(n,t)⁴He reaction yields a total Q value of 4.78 MeV, larger than ¹⁰B, an energy easily identified above background radiations. Hence, devices fabricated from semiconducting compounds containing either natural Li (nominally 7.5% ⁶Li) or enriched ⁶Li (usually 95% 6Li) may provide a semiconductor material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and P sealed under vacuum (10^-6 Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace. A static vacuum sublimation in quartz was then performed to remove the volatile impurities from the synthesized material. Samples from the sublimation process were analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), which showed that binaries and unreacted materials were sublimed out of the ternary material. Bulk crystalline samples were grown from the purified material. Individual samples were characterized for crystallinity on a Bruker AXS D8 DISCOVER, high-resolution x-ray diffractometer with a 0.004° beam divergence. The (220) oriented LiZnAs and LiZnP samples yielded rocking curves with a 0.235° full width at half maximum (FWHM) and 0.417° FWHM respectively.