Surface-morphology features are shown that are formed on a single crystal of zinc oxide by heating the material in zinc metal vapor. The structure reflects the six-fold symmetry of the surface of the ZnO crystal that was grown by a chemical vapor transport process.
The ORNL Synthesis and Properties of Novel Materials Group carries out research in the areas of the discovery, synthesis, single crystal growth, and characterization of radiation detection materials and devices. This research effort includes the growth of large, high quality halide single crystals, new phosphate single crystal scintillators, and glass and transparent polycrystalline ceramic scintillators. Research performed by the group has led to the discovery of an entire new family of rare-earth metal organic scintillating materials that are applicable to both gamma ray and high-energy neutron detection. The group has also carried out the design, fabrication and testing of new efficient proportional counters that do not use 3He for neutron detection. Additionally, the group engages in research on the single crystal growth of oxides, halides, phosphates, metals and alloys, and textured ceramics. Work has been performed in the area of the ion beam modification of materials and the use of ion beam methods to form smart near-surface composite materials and magnetic near surface composites. Other research activities include the growth and characterization of ferroelectric materials and metal-insulator materials. More recently the group’s research efforts have focused on the growth and characterization of conducting oxide single crystals. Studies of single crystal photo-anode materials for use in photoelectrochemical cells for hydrogen production have been carried out. Single crystals of stainless steel (a pure ternary alloy of iron, nickel, and chromium) have been grown and used in fundamental studies of solidification phenomena and welding science. Previously, the group worked in the field of developing new high durability ceramic and glass materials for nuclear waste disposal. Research has been carried out on the development of optical materials in both single crystal and amorphous forms. The synthesis capabilities of the group include systems for spark plasma sintering (SPS), hot pressing, and single crystal growth using the Czochralski technique, vertical Bridgman growth, high temperature solution (flux) methods, aqueous and organic solution methods, and float zone growth.
|BOATNER, Lynn A.