Bulk crystal growth, and high-resolution x-ray diffraction results of LiZnP semiconductor material

Nowotny-Juza compounds continue to be explored as a candidate for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present clay gas-filled He-3 and (BF3)-B-10 detectors. The Li-6(n,t)He-4 reaction yields a total Q-value of 4.78 MeV, larger than B-10, an energy easily identified above background radiations. Hence, devices fabricated from semiconducting compounds containing either natural Li (nominally 7.5% Li-6) or enriched Li-6 (usually 95% Li-6) 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 [1]. The synthesized material showed signs of high impurity levels from material and electrical property characterizations. A static vacuum sublimation in quartz was performed to help purify the synthesized material [2]. Bulk crystalline samples were grown from the purified material. An ingot 9.6 mm in diameter and 4.0 mm in length was harvested. Individual samples were characterized for crystallinity on a Bruker AXS Inc. D2 CRYSO, energy dispersive x-ray diffractometer, and a Bruker AXS D8 DISCOVER, high-resolution x-ray diffractometer with a 0.004 degrees beam divergence. The (220) orientation was characterized as the main orientation with the D2 CRYSO, and confirmed with the 08 DISCOVER. An out-of-plane high-resolution rocking curve yielded a 0.417 degrees full width at half maximum (FWHM) for the (220) LiZnP. In-plane ordering was confirmed by observation of the (311) orientation, where a rocking curve was collected with a FVVHM of 0.294 degrees. (C) 2015 Elsevier B.V. All rights reserved.