The discovery of high thermoelectric performance in n-type polycrystalline Mg3(Sb,Bi)2 based Zintl compounds has ignited intensive research interest. However, some fundamental questions concerning the anisotropic transport properties and the origin of intrinsically low thermal conductivity are still elusive, requiring the investigation of single crystals. In this work, high-quality p-type Mg3Sb2 and Mg3Bi2 single crystals have been grown by using a self-flux method. The electrical resistivity \r{ho} of Mg3Bi2 single crystal displays an anisotropy with \r{ho} in-plane twice larger than out-of-plane. The low-temperature heat capacity and lattice thermal conductivity of Mg3Sb2 and Mg3Bi2 single crystals have been investigated by using the Debye-Callaway model, from which the existence of low-lying vibration mode could be concluded. Large Grüneisen parameters and strong anharmonicity are found responsible for the intrinsically low thermal conductivity. Moreover, grain boundary scattering does not contribute significantly to suppress the lattice thermal conductivity of polycrystalline Mg3Sb2. Our results provide insights into the intrinsic transport properties of Mg3X2 and could pave a way to realize enhanced thermoelectric performance in single-crystalline Mg3X2-based Zintl compounds.
We examine the molecular dynamics of crystal growth in the presence of surface melting and surface impurities, and from this propose a detailed microscopic model for the growth of ice from the vapor phase. Our model naturally accounts for many aspects of the experimental data that are otherwise difficult to explain, and it suggests a variety of measurements that can provide further confirmation. Although additional work is needed to refine these ideas, we believe that the combined influences of surface melting and impurities provide a viable solution to the 60-year-old mystery of why snow crys…
We review several aspects of aerodynamics that affect the growth, morphology, and symmetry of snow crystals. We derive quantitative estimates for aerodynamical forces that orient falling snow crystals, estimate how air flow around snow crystals affects their growth rates (the ventilation effect), and examine how the combination of orientation and growth modification can stabilize or destabilize different growth behaviors. Special attention is given to the formation of triangular snow crystals, since it appears that aerodynamical effects are responsible for producing this unusual morphology, bo…
The authors of the title paper (Spectrochim. Acta 79A (2011) 340-343) report the crystal growth of cadmium manganese thiocyanate CdMn(SCN)4 and its characterization by single crystal X-ray diffraction and infrared spectrum. Many points of criticism, concerning the crystal growth and reported experimental data are highlighted in this report.
We present an investigation of chemical influences on the growth of ice crystals from water vapor. In one set of experiments, we grew ice crystals in a vapor diffusion chamber, observing crystal morphologies at temperatures from 0 C to -25 C in different background gases and with a variety of gaseous chemical additives. In a second set of experiments, we measured ice crystal growth rates at -5 C and -15 C in a free-fall flow chamber, using normal laboratory air and ultra-clean nitrogen gas, both with and without chemical additives. Conclusions from these experiments include:\ 1) In nitrogen ga…
We describe an apparatus designed for obtaining precise measurements of the growth rates of ice crystals from water vapor over a range of experimental conditions. Our aim is to produce clean, high-quality test crystals in a well controlled environment for investigating the detailed molecular dynamics that controls the basic physics of ice crystal growth. In this paper we describe the nucleation and initial growth of test crystals, their transport and selection into a experimental chamber, the creation of a stable and controllable supersaturation, hardware and calibration issues, and the crysta…
We propose a new type of morphological instability in the diffusion-limited growth of faceted crystals from the vapor phase that can explain the formation of thin ice plates at temperatures near -15 C. The instability appears when the attachment kinetics for facet growth depends strongly on the morphology of the facet surface. In particular, we propose that the condensation coefficient for growth of ice prism facets increases dramatically when the width of the facet approaches atomic dimensions. This model reconciles several conflicting measurements of ice crystal growth, and makes additional …
This application note describes how to model diffusion-limited crystal growth from vapor using QuickField - a commercial finite-element analysis code. The crystal growth problem is cast into the format of a steady-state heat diffusion problem, which is one type of problem QuickField is designed to solve, and we derive the relevant conversion factors and correspondences between variables. We also describe three types of boundary conditions in the crystal growth problem and their corresponding boundary conditions in the heat diffusion problem. As an example, we examine the crystal growth of ice …
We present experiments investigating the growth of ice crystals from water vapor in air using a free-fall convection chamber. We measured growth rates at temperatures of -5 C and -10 C as a function of supersaturation at an air pressure near one bar. We compared our data with numerical models of diffusion-limited growth based on cellular automata to extract surface growth parameters at different temperatures and supersaturations. From these investigations we hope to better understand the surface molecular dynamics that determine crystal growth rates and morphologies.
We describe laboratory-grown snow crystals that exhibit a triangular, plate-like morphology, and we show that the occurrence of these crystals is much more frequent than one would expect from random growth perturbations of the more-typical hexagonal forms. We then describe an aerodynamic model that explains the formation of these crystals. A single growth perturbation on one facet of a hexagonal plate leads to air flow around the crystal that promotes the growth of alternating facets. Aerodynamic effects thus produce a weak growth instability that can cause hexagonal plates to develop into tri…
We derive a set of algorithms for simulating the diffusion-limited growth of faceted crystals using local cellular automata. This technique has been shown to work well in reproducing realistic crystal morphologies, and the present work provides a more rigorous physical foundation that connects the numerical code to the physics of attachment kinetics and diffusion dynamics. We then apply these algorithms to examine a novel morphological transition in the growth of thin plate-like crystals.
We present observations of the formation of plate-like snow crystals that provide evidence for an edge-enhancing crystal growth instability. This instability arises when the condensation coefficient describing the growth of an ice prism facet increases as the width of the facet becomes narrower. Coupled with the effects of particle diffusion, this phenomenon causes thin plate-like crystals to develop from thicker prisms, sharpening the edges of the plates to micron or sub-micron dimensions as they grow. This sharpening effect is largely responsible for the formation of thin plate-like ice crys…
We describe observations of a novel hysteresis behavior in the growth of ice crystals under near-vacuum conditions. Above a threshold supersaturation, we find that the ice growth rate often exhibits a sudden increase that we attribute to an impurity-driven growth instability. We examine possible mechanisms for this instability, which can be used to produce clean, faceted ice surfaces.
The purpose of this paper is to review some elasticity effects in epitaxial growth. We start by a description of the main ingredients needed to describe elasticity effects (elastic interactions, surface stress, bulk and surface elasticity, thermodynamics of stressed solids). Then we describe how bulk and surface elasticity affect growth mode and surface morphology by means of stress-driven instability. At last stress-strain evolution during crystal growth is reported.
We describe an experimental apparatus for making detailed morphological observations of the growth of isolated plate-like ice crystals from water vapor. Each crystal develops a plate-on-pedestal (POP) geometry, in which a large, thin, plate-like crystal grows out from the top edge of an initially prismatic seed crystal resting on a substrate. With the POP geometry, the substrate is not in contact with the growing plate (except at its center), so substrate interactions do not adversely affect the crystal growth. By controlling the temperature and supersaturation around the crystal, we can manip…
In this paper, on the basis of the set of simplified model state equations to represent the dynamic features of melt pulling method growth process, we constructed a simulation control system of Matlab Simulink and analyzed control features of state variables for the total growth process including shoulder growth process and the constant diameter growth process of single crystals such as Si and LiNbO3.
We report the first single crystal growth of the correlated metal LaNiO3 using a high-pressure optical-image floating zone furnace. The crystals were studied using single crystal/powder x-ray diffraction, resistivity, specific heat, and magnetic susceptibility. The availability of bulk LaNiO3 crystals will (i) promote deep understanding in this correlated material, including the mechanism of enhanced paramagnetic susceptibility, and (ii) provide rich opportunities as a substrate for thin film growth such as important ferroelectric and/or multiferroic materials. This study demonstrates the powe…
The L-arginine mixed potassium dihydrogenphosphate (KDP) crystal reported by Saravanan et al Indian J Pure App Phys 51 (2013) 254, is a dubious crystal. The reported unit cell parameters contradict the definition of the tetragonal crystal system.
To obtain crystalline thin films of alpha-Quartz represents a challenge due to the tendency for the material towards spherulitic growth. Thus, understanding the mechanisms that give rise to spherulitic growth can help regulate the growth process. Here the spherulitic type of 2D crystal growth in thin amorphous Quartz films was analyzed by electron back-scatter diffraction (EBSD). EBSD was used to measure the size, orientation, and rotation of crystallographic grains in polycrystalline SiO2 and GeO2 thin films with high spatial resolution. Individual spherulitic Quartz crystal colonies contain …
The growth morphology and the effects of surface reconstruction/relaxation of the habit faces on the crystal morphology of urea crystal are investigated from first principle using the Hartman-Perdok approach. A procedure has been developed to find out surface termination when a slab of d(hkl) thickness is created having {hkl} orientation. Slice energy of different habit faces have been computed and the attachment energy was calculated. The crystal growth morphology of the urea crystal has been drawn on the basis of computed attachment energies of different habit faces. The calculated crystal g…
Metal halide perovskites have recently emerged as promising materials for the next generation of optoelectronic devices owing to their remarkable intrinsic properties. In the growth of perovskite crystals, the substrates are essential and play a vital role. Herein, substrate engineering in the growth of perovskite crystals have been reviewed. Particularly, various modified strategies and corresponding mechanism based on the substrate engineering applied to the optimization of thickness, nucleation and growth rate are highlighted. Then the alterable adhesion to substrates will also be discussed…
We present a tutorial on the principles of crystal growth of intermetallic and oxide compounds from molten solutions, with an emphasis on the fundamental principles governing the underlying phase equilibria and phase diagrams of multicomponent systems.
When calcium titanate crystals are grown from stoichiometric melts, they crystallize in the cubic perovskite structure. Upon cooling to room temperature they undergo subsequent phase transitions to tetragonal and orthorhombic modifications. These phase transitions are disruptive and result in severely damaged crystals. This paper presents differential thermal analysis data for several prospective solvents, with the aim to identify a system offering the possibility to perform crystal growth of undistorted CaTiO$_3$ crystals by crystallizing them significantly below the melting point directly in…
Leibniz-Institut für Kristallzüchtung（莱布尼茨晶体生长研究所）；Institute of Physics, Poznan University of Technology（波兹南理工大学物理研究所）
By differential thermal analysis a concentration field suitable for the growth of Zr, Mg codoped strontium hexagallate crystals was observed that corresponds well with experimental results from Mateika and Laurien, J. Crystal Growth 52 (1981) 566-572. It was shown that the melting point of doped crystal is ca. 60 K higher than that of undoped crystals. This higher melting points indicates hexagallate phase stabilization by Zr, Mg codoping, and increases the growth window, compared to undoped SrO-Ga$_2$O$_3$ melts.
Ice crystals growing in highly supersaturated air at temperatures near -5 C exhibit a distinctive, nonplanar dendritic morphology that has not been previously documented or explained. We examine this structure and identify its most prominent features in relation to the ice crystal lattice. Developing a full 3D numerical model that reproduces this robust morphology will be an interesting challenge in understanding diffusion-limited crystal growth in the presence of highly anisotropic surface attachment kinetics.
The authors of the title paper report to have grown ammonium hydrogen L-tartrate (1) by use of L-glutamine and L-tartaric acid in 1:1 mole ratio. Many points of criticism pertaining to the characterization of 1 are described herein.
We present a series of experiments investigating the growth of ice crystals from water vapor in the presence of a background gas. We measured growth dynamics at temperatures ranging from -2 C to -25 C, at supersaturations between 0.5 and 30 percent, and with background gases of nitrogen, argon, and air at a pressure of one bar. We compared our data with numerical models of diffusion-limited growth based on cellular automata to extract surface growth parameters at different temperatures and supersaturations. These data represent a first step toward obtaining precision ice growth measurements as…
We present experimental data demonstrating the presence of structure-dependent attachment kinetics (SDAK) in ice crystal growth from water vapor near -5 C. Specifically, we find that the nucleation barrier on the basal edge of a thin-walled hollow columnar crystal is approximately ten times smaller than the corresponding nucleation barrier on a large basal facet. These observations support the hypothesis that SDAK effects play an important role in determining the growth morphologies of atmospheric ice crystals as a function of temperature.
We describe how surface interactions can affect the growth of ice crystal facets in contact with a substrate by lowering the normal nucleation barrier on the ice surface. We also describe how the resulting enhanced growth rates can produce systematic errors even when measuring the growth of facets not contacting the substrate. From an analysis of the diffusion dynamics we then develop a simple procedure for approximately correcting ice growth data, thus substantially reducing these systematic errors. We have found this technique to be quite useful for interpreting ice growth data and extractin…
We present the design of a general-purpose convection chamber that produces a stable environment for studying the growth of ice crystals from water vapor in the presence of a background gas. Crystals grow in free fall inside the chamber, where the temperature and supersaturation are well characterized and surprisingly uniform. As crystals fall and land on a substrate, their dimensions are measured using direct imaging and broad-band interferometry. We also present a parameterized model of the supersaturation inside the chamber that is based on differential hygrometer measurements. Using this c…
we show that the pure and thiourea-doped glycyl-L-alanine hydrochloride (GLAH and TU-GLAH) crystals claimed to have been grown by the authors of the title paper (Journal of Russian Laser Research, 34, 346-350 (2013)) are dubious crystals.
In the calculation of the formation enthalpy of a defect, a stress term accompanying the formation volume of the defect appears. This formation volume is conventionally interpreted as the difference in volume between crystals with and without the defect. When defect formation is investigated in the study of crystal growth, the interpretation is sometimes misused by separately treating the volumes of the defect and perfect crystal. However, these two quantities are inseparable, and only the difference between them has physical reality.
We performed a chirality-controlled crystal growth of transition metal disilicide NbSi$_{2}$ and TaSi$_{2}$ by using a laser-diode-heated floating zone (LDFZ) method. The crystal chirality was evaluated in the crystals of centimeters in length by performing single crystal X-ray diffraction as well as probing a spin polarization originating from chirality-induced spin selectivity (CISS) effect. The crystals of right-handed NbSi$_{2}$ and of left-handed TaSi$_{2}$ were obtained in the conventional LDFZ crystal growth, while the left-handed NbSi$_{2}$ and right-handed TaSi$_{2}$ crystals were gro…
We present measurements of the growth of long columnar ice crystals from water vapor over a broad range of temperatures and supersaturation levels in air. Starting with thin, c-axis ice needle crystals, we observed their subsequent growth behavior in a vapor diffusion chamber, extracting the initial radial growth velocities of the needles under controlled conditions. Approximating the hexagonal needle crystals as infinitely long cylinders, we created an analytical growth model that includes effects from particle diffusion of water molecules through the surrounding air along with the diffusion …
We present measurements of the diffusion-limited growth of ice crystals from water vapor at different supersaturation levels in air at a temperature of -15 C. Starting with thin, c-axis ice needle crystals, the subsequent growth morphologies ranged from blocky structures on the needle tips (at low supersaturation) to thin faceted plates on the needle tips (at high supersaturation). We successfully modeled the experimental data, reproducing both growth rates and growth morphologies, using a cellular-automata method that yields faceted crystalline structures in diffusion-limited growth. From thi…
This article presents a direct measurement of the growth angle during the growth of a cylindrical 2" silicon crystal using a radio-frequency heated floating zone process. From the high-resolution pictures taken during the process, this growth angle was evaluated to be 11°{\pm}2°. Furthermore, the free surface of the melt was modeled using the Laplace-Young equation. This model has to include the electromagnetic pressure calculated by the surface ring currents approximation. The results were compared to the experimental free surface derived from video frames. It could be shown that the calculat…
Gunasekaran et al (Pramana J. Phys. 75 683-690 (2010)) report to have grown the nonlinear optical crystals urea thiourea mercuric chloride (UTHC) and urea thiourea mercuric sulphate (UTHS). We argue that UTHC and UTHS are dubious crystals and are not what the authors propose.
We describe a novel crystal growth instability that enhances the development of thin edges, promoting the formation of plate-like or hollow columnar morphologies. This instability arises when diffusion-limited growth is coupled with structure-depdendent attachment kinetics, specifically when the nucleation barrier on a facet surface decreases substantially as the facet width approaches atomic dimensions. Experimental data are presented confirming the presence of this instability in the growth of ice from water vapor at -15 C. We believe this edge-enhancing effect plays an important role in det…
In this paper I examine snow crystal growth near -14 C in comparison with a comprehensive model that includes Structure-Dependent Attachment Kinetics (SDAK). Analyzing a series of ice-growth observations in air, I show that the data strongly support the model, which stipulates that basal growth is described by classical terrace nucleation on faceted surfaces in this temperature region. In contrast, prism growth exhibits a pronounced "SDAK dip" that substantially reduces the nucleation barrier on narrow prism facets (relative to that found on broad prism facets). I use these measurements to fur…
This report presents a new synthesis protocol for the single crystal growth of rare earth monopnictide DySb by self-flux technique. A detailed structural, transport and magnetic characterization have been done using X-Ray diffraction (XRD), High resolution X-Ray diffraction (HRXRD), resistivity and magnetization measurements respectively. The Rietveld refinement of powder XRD pattern confirms that the grown crystal is in single phase and crystallizes in space group Fm3m(225) of rock-salt type crystal structure. HRXRD on cleaved crystal confirms the single crystalline nature while rocking curve…
I examine a variety snow crystal growth experiments performed at temperatures near -2 C, as a function of supersaturation, background gas pressure, and crystal morphology. Although the different experimental data were obtained using quite diverse experimental techniques, the resulting measurements can all be reasonably understood using a single comprehensive physical model for the basal and prism attachment kinetics, together with particle diffusion of water vapor through the surrounding medium and other well-understood physical processes. As with the previous paper in this series, comparing a…
The evolution of a continuous Fe(NO3)3 catalyst film was observed by in-situ annealing in a Transmission Electron Microscope (TEM). Such catalysts are routinely used in the catalytic growth of carbon nanotubes. The experiments reveal that crystalline particles form from the gel-like film already around 300C. At usual carbon nanotube growth temperatures of 700C, the particles are single-crystalline with a log-normal size distribution. The observations furthermore show that in spite of the crystalline structure of the particles there is a high mobility. The experiments allow to obtain detailed i…
We use a new, quantum-mechanics-based bond-order potential (BOP) to reveal melt-growth dynamics and fine-scale defect formation mechanisms in CdTe crystals. Previous molecular dynamics simulations of semiconductors have shown qualitatively incorrect behavior due to the lack of an interatomic potential capable of predicting both crystalline growth and property trends of many transitional structures encountered during the melt $\rightarrow$ crystal transformation. Here we demonstrate successful molecular dynamics simulations of melt-growth in CdTe using a BOP that significantly improves over oth…
We present a method for the solution growth of single crystals from reactive Li and Ca melts and its application to the synthesis of several, representative compounds. Among these, single crystalline Li3N, Li2(Li{1-x}Tx)N with T = {Mn, Fe, Co}, LiCaN, Li2C2, LiRh, and LiIr from Li-rich flux as well as Ca2N, CaNi2, CaNi3, YbNi2, Y2Ni7, and LaNi5 from Ca-rich flux could be obtained. Special emphasize is given on the growth of nitrides using commercially available Li3N and Ca3N2 powders as the nitrogen source instead of N2 gas.
Germanium is an extremely important material used for numerous functional applications in many fields of nanotechnology. In this paper, we study the crystallization of amorphous Ge using atomistic simulations of critical nano-metric nuclei at high temperatures. We find that crystallization occurs by the recurrent transfer of atoms via a diffusive process from the amorphous phase into suitably-oriented crystalline layers. We accompany our simulations with a comprehensive thermodynamic and kinetic analysis of the growth process, which explains the energy balance and the interfacial growth veloci…
Crystal nucleation and growth processes induced by an externally applied shear strain in a model metallic glass are studied by means of nonequilibrium molecular dynamics simulations, in a range of temperatures. We observe that the nucleation-growth process takes place after a transient, induction regime. The critical cluster size and the lag-time associated with this induction period are determined from a mean first-passage time analysis. The laws that describe the cluster growth process are studied as a function of temperature and strain rate. A theoretical model for crystallization kinetics …
Transition metal dichalcogenides (TMDs) are van der Waals layered materials with sizable and tunable bandgaps, offering promising platforms for two-dimensional electronics and optoelectronics. To this end, the bottleneck is how to acquire high-quality single crystals in a facile and efficient manner. As one of the most widely employed method of single-crystal growth, conventional chemical vapor transport (CVT) generally encountered problems including the excess nucleation that leads to small crystal clusters and slow growth rate. To address these issues, a seed crystal is introduced to suppres…
Two 75mm 4H-SiC single crystals are grown by the physical vapor transport (PVT) technique, using different insulation materials. The insulation material of higher thermal conductivity led to an increased radial temperature gradient. The evolution of the growth front was monitored using the in-situ computed tomography (CT). A slightly bent growth interface and a bigger facet are formed during the growth applying a lower radial temperature gradient while a smaller facet and steeper crystal flanks are formed in the case of the larger radial temperature gradient. Micropipes are deflected laterally…
The unit cell parameters, infrared and UV-Vis spectral data reported in the paper by Vijayabhaskaran et al (Indian J Pure & App Phys 49 (2011) 340-343) cannot belong to the colourless crystalline compound formulated as copper mercury thiocyanate CuHg(SCN)4 as claimed by the authors.
We have grown a single crystal of the equiatomic FeCoCrMnAl high-entropy alloy. The crystal was grown by means of the Bridgman technique and is about 1 cm in diameter and 6.6 cm in length. X-ray Laue images taken at various positions on the surface are sharp and mutually consistent, reflecting its single-crystal nature. We thus report on the first successful growth of a single crystal of a high-entropy alloy with a volume of the order of cubic centimeters. The material has a microstructure consisting of B2 inclusions in a body-centered cubic matrix on the 10 nm length scale.
First single crystal fibers of cerium doped strontium yttrate are fabricated using the laser-heated pedestal growth technique. Through thermodynamic equilibrium calculations and by high-temperature mass spectrometry suitable growth conditions can be determined. The atmosphere plays an important role during crystallization. It affects the composition shift, on the one hand, and the valence state of cerium, on the other hand. These properties can be explained by combining X-ray diffraction, elemental analysis, and optical spectroscopy. Crystallization in slightly reducing nitrogen atmosphere pro…
We examine ice crystal growth from water vapor at temperatures near the melting point, when surface premelting creates a quasiliquid layer at the solid/vapor interface. Recent ice growth measurements as a function of vapor supersaturation have demonstrated a substantial nucleation barrier on the basal surface at these temperatures, from which a molecular step energy can be extracted using classical nucleation theory. Additional ice growth measurements from liquid water as a function of supercooling exhibit a similar nucleation barrier on the basal surface, yielding about the same molecular ste…
I describe a new approach to the classification of snow crystal morphologies that focuses on the most common growth behaviors that appear in normal air under conditions of constant applied temperature and water-vapor supersaturation. The resulting morphological structures are generally robust with respect to small environmental changes and thus should be especially amenable to computational modeling. Because spontaneous structure formation depends on initial conditions, the choice of seed crystal can be an important consideration, and I have found that slender c-axis ice needles provide an exc…
We describe a dual diffusion chamber for observing ice crystal growth from water vapor in air as a function of temperature and supersaturation. In the first diffusion chamber, thin c-axis ice needles with tip radii ~100 nm are grown to lengths of ~2 mm. The needle crystals are then transported to a second diffusion chamber where the temperature and supersaturation can be independently controlled. By creating a linear temperature gradient in the second chamber, convection currents are suppressed and the supersaturation can be modeled with high accuracy. The c-axis needle crystals provide a uniq…
Interface energy and kinetic coefficient of crystal growth strongly depend on the face of the crystalline lattice. To investigate the kinetic anisotropy and velocity of different crystallographic faces we use the hyperbolic (modified) phase field crystal model which takes into account atomic density (as a slow thermodynamic variable) and atomic flux (as a fast thermodynamic variable). Such model covers slow and rapid regimes of interfaces propagation at small and large driving forces during solidification. In example of BCC crystal lattice invading the homogeneous liquid, dynamical regimes of …
The slow evaporation of an aqueous solution containing L-valine and salicylic acid results in the fractional crystallization of salicylic acid and not any so called L-valinium salicylate as reported recently by Andal and Murugakoothan in the title paper.
A description is given of the traveling solvent technique, which has been used for the crystal growth of both congruently and incongruently melting materials of many classes of intermetallic, chalcogenide, semiconductor and oxide materials. The use of a solvent, growth at lower temperatures and the zoning process, that are inherent ingredients of the method, can help to grow large, high structural quality, high purity crystals. In order to optimize this process, careful control of the various growth variables is imperative; however, this can be difficult to achieve due to the large number of i…
CuFeO$_2$ single crystals up to 50 mm in length and up to 10 mm in diameter were grown by the optical floating-zone method. Stoichiometric polycrystalline rods with a diameter of 6-12 mm were used as feed materials to produce crystals of sufficient size to be used as substrates for the growth of thin films of delafossites. For stable growth along the $c$-axis, low growth rates of 0.4 mm/h are necessary. Due to the incongruent melting behavior of CuFeO$_2$, a stable melt zone requires adjustment of the lamp power during growth. The melting of CuFeO$_2$ is not simply incongruent because the ther…
The methodology of single crystal growth of metastable $β$-Ti alloy TIMETAL LCB in an optical floating zone furnace is presented in this paper. Chemical compositions of both precursor material and single crystals were checked. It was found that the concentration of base alloying elements did not change significantly during the growth process, while the concentrations of interstitial elements O and N increased. DSC measurement determined that this concentration shift has a slight impact on ongoing phase transformations, as in the single-crystalline material peak associated with $α$ phase precip…
