Static sublimation purification process and characterization of LiZnP semiconductor material

Refinement of the class A^IB^IIC^V materials continue as a candidate for solid-state neutron detectors. Such a device 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, and easily identified above background radiations. Hence, devices composed of either natural Li (nominally 7.5% ⁶Li) or enriched ⁶Li (usually 95% ⁶Li) may provide a semiconductor material for compact high efficiency neutron detectors. A sub-branch of the III-V semiconductors, the filled tetrahedral compounds, A^IB^IIC^V, known as Nowotny-Juza compounds, are known for their desirable cubic crystal structure. Starting material was synthesized by combining equimolar portions of Li, Zn, and P sealed under vacuum (10^-6 Torr) in quartz ampoules, having boron nitride liners, and subsequently reacted in a compounding furnace (Montag et al., 2015, J. of Cryst. Growth). A static vacuum sublimation in quartz was performed to help purify the synthesized material. The chemical composition of the sublimed material and remaining material was confirmed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Lithium was not detected in the sublimed material, however, approximately stoichiometric concentrations of each constituent element were found in the remaining LiZnP material. X-ray diffraction phase identification scans of the remains material and sublimed material were compared, and further indicated the impurity materials were sublimed away from the synthesized materials. The resulting material from the sublimation process showed characteristics of a higher purity ternary compound.