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Single crystals of U3Si2 and U3Si5 were grown using the modified Czochralski tri-arc growth technique in a gettered argon atmosphere. A variety of growth parameters including seed pull rate, seed rotation rate, crystal size, charge size and stoichiometry were evaluated to determine the best growth conditions in an effort to produce high quality single crystals for property measurements and basic studies. The crystals were characterized for quality, phase purity, density, and axial variations in chemistry. Near phase-pure, single crystals 5 mm in diameter and 35 mm in length were grown with minimal variation in stoichiometry and limited cracking using a crystal rotation rate of 30 rpm, a hearth rotation rate of 22 rpm, and a pull rate of 16 mm/h up to solidified fraction of g = 0.75.

Single crystal La 2/3 Sr 1/3 MnO 3− δ manganite with an unusual structure was obtained by the optical-floating method with controlled growth in a flowing argon atmosphere. A modulated twin-like structure with phase separation characteristics in the long-range order is found. The energy-dispersive X-ray spectroscopy measurement reveals that there is a strong chemical fluctuation for different stripes, i.e. resulting from the nonstoichiometry due to oxygen deficiency. After annealing, the twin-like stripe phase disappears and the single crystal shows excellent properties. These results may be of great significance for controlled growth of oxide electronics materials with artificial superstructure-like technique.

MnSi and MnSi 2- single crystals were grown from high temperature gallium metal fluxes by slowly cooling the melt in argon atmosphere. The growth conditions of MnSi and MnSi 2-x (Mn 15 Si 26 ) crystals with relatively large size, namely MnSi about 0.06 x 0.52 x 2.43 mm 3 and Mn 15 Si 26 about 0.40 × 0.55 x 0.61 mm 3 were established. MnSi crystals were generally obtained in the form of needle-like prisms extending in the direction and with well-developed (111) faces. Mn 15 Si 26 crystals had a nearly spherical polyhedral shape, greyish color and metallic luster. The as-grown MnSi and Mn 15 Si 26 crystals were used for chemical analyses and measurements of unit cell parameters. Vickers microhardness was determined on MnSi and Mn 15 Si 26 crystals, and oxidation at high temperature in air was studied for MnSi and Mn 15 Si 26 crystals.

For the study of isotope effects in ZnSe, 64 Zn and 68 Zn isotopes have been combined with 76 Se and 80 Se isotopes. Synthesis, purification and crystal growth were carried out via the vapor phase in the same sealed ampoule. The 〈1 1 1〉 directed growth was favored by repeated formation of twins. Rod-shaped crystals up to 8 mm in length were obtained from small quantities of source materials. The physical vapor transport in an argon atmosphere with a Zn reservoir has been studied quantitatively.

Single crystals of the fullerene C60 are grown by the Pizzarello method in an argon atmosphere. A C60 nucleus is formed ahead of the growing crystal when a drive rate greater than the limited mass-transfer rate is used. The analysis of the crystal growth rates and temperature distribution reveals a constitutional supersaturation which causes this particular type of nucleation.

We have determined that hexagonal single crystals of layer-structured germanium (II) iodide (GeI 2 ) up to 1.5 cm in diameter can be grown in a vapor reaction system. Specific initial conditions for optimum growth require the high temperature end of the reaction ampoule to be between 330 and 336°C in a neutral internal argon atmosphere of less than 10 −3 Torr. New powder X-ray diffraction data yield a c -axis of 6.828 ± 0.004 A and an a -axis of 4.251 ± 0.003 A .

Single crystals of the fullerene C 60 were grown by the Pizzarello method in an argon atmosphere. The growth in a cone was investigated as a function of the drive rate. The binary diffusion coefficient was estimated from the difference between the drive rate and crystal growth velocity. The critical supersaturation was evaluated from the maximum crystal length which appeared in the stage of resublimation if the drive direction was changed.

A laser heated floating zone method is applied to the growth of filamentary LaB 6 single crystals. Crystal growth is carried out in an argon atmosphere of normal pressure. Although vaporization is observed during the growth process, decomposition of LaB 6 does not occur. Inclusions are occasionally observed in single crystals grown under inadequate diameter control. It is found that these inclusions are LaB 4 . They are formed because the composition of the feed material is different from the congruent composition. Inclusions can be eliminated by carefully controlling the laser output to maintain a constant molten zone height. As a result, inclusion free single crystals, 1 mm in diameter and 50 mm in length, with a 〈100〉 growth axis are obtained. These crystals provide available electron emitters.

The epitaxial growth of high purity GaAs has been carried out successfully with a leak-free and corrosion resistant AsCl 3 -Ga-Ar system. A background free carrier concentration of 7.35 × 10 12 cm -3 , a mobility of 2.05 × 10 5 cm 2 /V · s at 77 K, a peak mobility of 3.78 × 10 5 cm 2 /V · s at 35 K and a thickness of 18.0 μm were achieved by careful control of growth conditions. The effects of deposition temperature on the growth rate and mobility at 77 K were investigated in H 2 , N 2 and Ar systems respectively. It was found that the Ar system has an advantage over the N 2 system in growing high purity GaAs, especially in growing thinner epilayers. The residual impurities in high purity epilayers were investigated by IMMA and photoluminescence measurements. By these analyses one can see that the Si contamination is suppressed in the Ar system as effectively as in the N 2 system, and the dominat residual acceptor impurity of the high purity epilayer grown in the Ar system is carbon.

Gold decoration in situ of lateral {001} faces of NaCl ingot, pulled by the Czochralski method in a dry argon atmosphere, reveals two-dimensional nuclei of monoatomic height which are supposed to be formed during the growth from the melt. The absence of any system of equidistant growth steps may be explained by a very low concentration of dislocations at the freezins point. Most dislocations must then result from thermal stresseg at lower temperature. The observed distribution of etch-pits throughout the volume of the ingot seems to prove this hypothesis.

Seven eutectic alloys (Pb-- Sb, Bi-- Cd, Zn-- Zn/sub 3/Sb/sub 2/, Bi-- BiPb/su b 2/, Bi-- Sn, Bi-- Zn, and Sn-- Zn) made from 99.99% purity components were zone-refined in argon atmosphere to reduce further their impurity content. The zone-refined alloys were zone-leveled and directionally solidified. Several basic morphological changes were observed: coarsening (Pb-- Sb), orientation of the minor phase along growth direction, some breakdown of regularity in the complex regular structure (Bi-- BiPb/sub 2/, Bi-- Sn), and horizontal alignment of the minor phase by rotation about the growth axis (Bi-- Cd, Bi-- Zn, Sn-- Zn). Three classes of refined structures were obtained: irregular (Pb-- Sb, Bi-- BiPb/ sub 2/, Bi-- Sn), brokenlamellar (Bi-- Cd, Br-- Zn), and broken-rod (Zn-- Zn/sub 3/Sb/sub 2/, Sn-- Zn).

Large single crystals of LiBO2 and Li2B4O7 containing both natural lithium and isotopically pure 6Li have been grown from the melt using the Czochralski technique. The melt was contained in a nickel crucible under a high purity argon atmosphere. Counter rotation of the melt and seed at 10 rpm and a pulling rate of 2.5 mm h-1 gave the best results. In the case of Li2B4O7 slow cooling of the boule over two days was necessary in order to prevent severe cracking. Even under these conditions some cracking could not be avoided. For LiBO2 a strong growth preference along (010) was observed. Growth rates normal to the preferred direction were also anisotropic, producing unusual wedge-shaped crystals. Li2B4O7 could be grown along (102) with no marked growth preference normal to this direction.

The thermal stability of colourless 6H and 15R type SiC single crystals was compared with each other at 2500 °C in an argon atmosphere. In the experiment, single crystals of both types were placed in a small graphite capsule and heated for 8hr. The 15R type crystal had evaporated away and the 6H type crystal grew at its expense. From this result it is concluded that under these conditions the 6H type crystal has a higher thermal stability than the 15R type crystal.

V2O3 single crystals were grown in a Stockbarger furnace in an argon atmosphere, by the reduction of V2O5 in molten KF. Graphite served both as crucible material and reducing agent. The crystals obtained were of good stoichiometry, high purity and measured up to 6.5 mm across and over 2 mm thick.