[en] In the present paper investigation results of photoluminescence of spectra doped by silicon and arsenide Ga epitaxial layers created from liquid-phase of different content are studied. Bi and Ga were used as a metals-solvent. In this case Bi and Ga contents in solution-melt are changed. Free electrons concentration at 300 K in epitaxial layers constitutes (1-3)·10¹⁷ cm ^-3. Photoluminescence excitation was made continuous emit time of He-Ne laser Lg-75 with length wave of λ=632,8 mm. The maximum excitation level was ∼10¹⁸ ph/cm²·s. Photoluminescence with help of focusing mirror was focused on entrance slot of monochromator MDR-23. The filter Ks-19 is installed in order to avoid scattered emittance ingress into monochromator in front of entrance slot. It is shown that photoluminescence spectra shift within longwave field with increase Bi content in solution-melt is connected with Si_Ga Cu_Ga deep center formation

[en] In this paper I present an example of the research that the Mineral Surface Group of the Munster University is conducting in the field of Crystal Growth. Atomic Force Microscopy (Am) in situ observations of different barite (BaSO4) faces growing from aqueous solutions, in combination with computer simulations of the surface attachment of growth units allows us to test crystal growth models. Our results demonstrate the strong structural control that a crystal can exert on its own growth, revealing also the limitation of the classical crystal growth theories (two dimensional nucleation and spiral growth models) in providing a complete explanation for the growth behaviour at a molecular scale. (Author) 6 refs

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[en] InSe:Er single crystal was grown by using the Stockbarger method. The growthed InSe:Er single crystal ingots were 12 mm in diameter and about 80 mm in length. The absorption measurements were carried out for U=0 and U=40 V states of InSe:Er sample in the temperature range of 10-320 K. Binding energies for U=0 and U=40 V states were calculated to be (4.25±0.04) and (3.25±0.04) MeV respectively. At 10 K, direct band gaps of U=0 and U=40 V states of InSe:Er are 1.322 and 1.315 eV and indirect band gaps are 1.313 and 1.308 eV, respectively. The steepness parameters and Urbach energy for the U=0 and U=40 V states in InSe:Er sample increased with increasing sample temperature in the range 10-320 K

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[en] Rare earth titanate pyrochlores are known to exhibit magnetic frustration. Large, high quality single crystals of a series of oxide pyrochlores, R₂Ti₂O₇, have been grown by the floating zone technique, using an infrared image furnace. The crystals are roughly 5 - 6 mm in diameter and 40 - 60 mm in length and have been grown for R = Pr, Nd, Sm, Tb, Dy, Ho, Er and Y. The crystals have been characterized and tested for their quality. (author). Letter-to-the-editor

[en] X-ray back-reflection topography with TV and photoplates recording as well as X-ray analysis technique have been applied to a number of sapphire single crystals shaped as 90 angles and tubes. It was done to study the formation and evolution of dislocation and mosaic structure in the shaped crystals with complicated cross-section. It has been shown that the real-structure formation in the origin part of the all shaped crystals, corresponding to its seeding and growing up to the steady-state dimensions has a principal significance for the next growth stages. The rotation of tube crystal orientation around its growth direction was first discovered and measured. The curl of tube crystals is discussed as one of the essential mechanisms of mosaic structure development and as some reaction of tube crystal to growth conditions

[en] Homogeneous SiGe crystal growth experiments will be performed on board the ISS 'Kibo' using a gradient heating furnace (GHF). A new crystal growth method invented for growing homogeneous mixed crystals named 'travelling liquidus-zone (TLZ) method' is evaluated by the growth of Si_0.5Ge_0.5 crystals in space. We have already succeeded in growing homogeneous 2mm diameter Si_0.5Ge_0.5 crystals on the ground but large diameter homogeneous crystals are difficult to be grown due to convection in a melt. In microgravity, larger diameter crystals can be grown with suppressing convection. Radial concentration profiles as well as axial profiles in microgravity grown crystals will be measured and will be compared with our two-dimensional TLZ growth model equation and compositional variation is analyzed. Results are beneficial for growing large diameter mixed crystals by the TLZ method on the ground. Here, we report on the principle of the TLZ method for homogeneous crystal growth, results of preparatory experiments on the ground and plan for microgravity experiments.

[en] Bismuth and lead crystals are used as gamma radiation filters more efficient than their amorphous state. In order to get crystals from these materials, a Bridgman-type crystal growth stove was built. It was possible to increase little crystals of Bi and Pb of few volume cubical centimeters, performing on the reached samples tests guaranteeing its crystalline arrangement exact as the Laue scattering

No abstract available