Showing papers in "Journal of Crystal Growth in 1969"

TL;DR: In this paper, it was shown that surface diffusion plays an essential role in the growth process and that the observed shapes of spirals and habits of crystals described in terms of the morphological theory of Hartman and Perdok can be explained on the basis of the surface diffusion model of Burton, Cabrera and Frank.

TL;DR: In this paper, the development of a cellular solid-liquid interface from a planar interface is outlined in some detail for a dilute binary alloy of Sb in zone-refined Pb.

TL;DR: In this article, single crystals of rare-earth orthophosphates (RPO4), arsenates, and vanadates have been grown by a flux method with use of an oscillating-temperature procedure.

TL;DR: In this paper, the isothermal evaporation method was used to grow the rare earth orthochromites RCrO3 (R = La to Yb) and lanthanum aluminate crystals doped with more than 0.1% Cr3+; in all cases 5 mm edge crystals were obtained.

TL;DR: In this article, an approximate solution has been obtained for the distribution of solvent in an unstirred melt under the growth conditions typical of liquid epitaxy, where the growth rate will be limited by the rate at which solvent can be removed from the growing interface.

TL;DR: Iodine concentrations, temperature gradients and transport ampules etching effects on mass transport rate and crystal growth of MnS-MnSe- iodine system were studied in this paper.

TL;DR: In this article, the etch pit structure of solution grown cyclotrimethylene trinitramine (RDX, cyclonite) has been investigated and dislocations characterised using the pit technique.

TL;DR: In this paper, the authors describe microstructures and composition variations at quenched planar or cellular solid-liquid fronts in A 1 −2 wt% Cu and suggest that the initial spacing represents the wave length of successful perturbations of the steady state fronts, and that dendrite spacings do not subsequently change.

TL;DR: In this paper, a new method has been devised to pull crystal ribbons from the free surface of a melt without using a shaping aperture, in which the crystal ribbon is pulled in a direction parallel to the melt surface while the heat of crystallization is removed in adirection perpendicular to the melted surface with a heat sink in contact with the upper surface of the ribbon.

TL;DR: In this paper, a numerical method is used to compute the growth behavior of spherical crystal nuclei in highly supercooled liquids, and the effects of interface curvature, interface attachment kinetics and fully time-dependent heat flow are included in the method.

TL;DR: In this paper, conditions for nucleation control and growth of large single crystals of CdS in a closed system are investigated both in the case of sublimation and iodine transport.

TL;DR: In this paper, single crystal ice cylinders have been grown into undercooled water and the growth rates of perturbations along the axis of the cylinder yield a value of 0.022 J/m 2 (22 erg/cm 2 ) for the ice-water surface tension of planes parallel to the c -axis.

TL;DR: In this paper, the authors analyzed the migration of droplets of aqueous solutions through ice under a temperature gradient driving force and found that the migration rate was limited, in part, by interface attachment kinetics.

TL;DR: In this paper, the collision breeding of MgSO 4 ṡ 7H 2 O has been studied under conditions in which the parent crystal is pre-treated to eliminate the initial breeding process, and in which, by using very short periods of agitation, only first generation nuclei are counted.

TL;DR: In this article, the effect of convective mixing of solute in the melt (expressed in terms of a boundary layer thickness) on the onset of interface instability is considered, and it is shown that the modified constitutional supercooling criterion of Mullins and Sekerka remains valid under most experimental situations but that their region of absolute stability exists only in the absence of mixing.

TL;DR: In this article, the Stockbarger technique was used to grow LiYF 4 at a rate of 0.6 mm/hr in a temperature gradient of 100°C/m from a melt of 48% YF 3 and 52% LiF under a pressure of 500 mm nitrogen.

TL;DR: In this paper, the authors considered the series of molecular configurations through which a crystal surface must pass in order to grow and derived an expression for the growth rate of a crystal in terms of the probabilities of molecules joining and leaving each of the configurations.

TL;DR: In this paper, it was suggested that the tendency for hydrogen bonding in aqueous solutions is an added factor in reducing the rate of nucleation in the case of citric acid.

TL;DR: The cell to dendrite transition during Pb-Sb alloy solidification was characterized by a gradual and continuous change in the cell cross-section rather than by the sudden growth of periodic secondary branches as discussed by the authors.

TL;DR: In this article, a theory predicting the dependence of the effective distribution coefficient on the amplitude and frequency of temperature fluctuations in the melt is developed from which it is shown that temperature fluctuations decrease the average degree of segregation.

TL;DR: In this paper, the authors used a CO2 laser to heat a crucible-free zone with a coaxial heating source, by which the radial temperature gradient may be essentially reduced.

TL;DR: In this article, single crystals of ZnSe have been grown by the gradient freeze technique from a stoichiometric melt in a sealed hot-walled system, which allows the incorporation of dopants of high vapor pressure and maintainance of stoichiometry.

TL;DR: In this paper, the authors describe the preparation of polycrystalline gallium sulphide with a minimum impurity content, and the results of the analysis of the gallium sulfide are presented.

TL;DR: In this paper, a macroscopic model for the habit of growth of a crystal of an arbitrary shape is presented, defined as a first approximation of the real one, which predicts the reappearance and disappearance of a given crystallographic face or edge of the grown crystal.

TL;DR: In this paper, the crystal growth of some fluorides such as AlF 3, CrF 3, NiF 2, KNiF 3 and CoF 2 by the flux method is reported.

TL;DR: In this paper, single crystals of Bi 4 (GeO 4 ) 3 have been grown from a rf heated platinum crucible by the Czochralski method and their dimensions reach up to 75 mm length and 25 mm diameter.

TL;DR: In this article, the linear velocity of crystallization I for pure components and eutectics was found to depend on Δ according to the equation I = K ( ΔT ) n, where K and n are constants.

TL;DR: The application of the Stockbarger technique to the growth of single crystals of ternary sulphides has been investigated in this paper, where single crystals were obtained from the constituent binary sulphides and the basic elements.

TL;DR: In this paper, a model is proposed to explain the various forms in which CdS grows by synthesis of its constituting elements, based on the fact that the growth of the crystals occurs in a non-stoichiometric medium.

TL;DR: The transition from diffusion growth to diffusionless growth is traced on the basis of the derived relationship between the degree of short-range order in the new phase and the magnitude of the coefficient of diffusion as discussed by the authors.