Growth Of Single Crystals Research Articles

Metal halide perovskite single crystal growth and application for X-ray detectors

This review provides an overview of the growth of perovskite single crystals and their recent development in X-ray detectors.

Liquid Cu–Zn catalyzed growth of graphene single-crystals

The controllable synthesis of millimeter-sized single-crystal monolayer graphene on a liquid Cu–Zn alloy by suppressing nucleation is reported.

Crystal phase engineering of silicene by Sn-modified Ag(111).

The synthesis of silicene by direct growth on silver is characterized by the formation of multiple phases and domains, posing severe constraints on the spatial charge conduction towards a technological transfer of silicene to electronic transport devices. Here we engineer the silicene/silver interface by two schemes, namely, either through decoration by Sn atoms, forming an Ag2Sn surface alloy, or by buffering the interface with a stanene layer. Whereas in both cases Raman spectra confirm the typical features as expected from silicene, by electron diffraction we observe that a very well-ordered single-phase 4 × 4 monolayer silicene is stabilized by the decorated surface, while the buffered interface exhibits a sharp phase at all silicon coverages. Both interfaces also stabilize the ordered growth of a phase in the multilayer range, featuring a single rotational domain. Theoretical ab initio models are used to investigate low-buckled silicene phases (4 × 4 and a competing one) and various structures, supporting the experimental findings. This study provides new and promising technology routes to manipulate the silicene structure by controlled phase selection and single-crystal silicene growth on a wafer-scale.

Bulk Physical Properties of a Magnetic Weyl Semimetal Candidate NdAlGe Grown by a Laser Floating-Zone Method

In this study, we report the successful growth of single crystals of a magnetic Weyl semimetal candidate NdAlGe with the space group I41md. The crystals were grown using a floating-zone technique, which used five laser diodes, with a total power of 2 kW, as the heat source. To ensure that the molten zone was stably formed during the growth, we employed a bell-shaped distribution profile of the vertical irradiation intensity. After the nominal powder, crushed from an arc-melted ingot, was shaped under hydrostatic pressure, we sintered the feed and seed rods in an Ar atmosphere under ultra-low oxygen partial pressure (<10−26 atm) generated by an oxygen pump made of yttria-stabilized zirconia heated at 873 K. Single crystals of NdAlGe were successfully grown to a length of 50 mm. The grown crystals showed magnetic order in bulk at 13.5 K. The fundamental physical properties were characterized by magnetic susceptibility, magnetization, specific heat, thermal expansion, and electrical resistivity measurements. This study demonstrates that the magnetic order induces anisotropic magnetoelasticity, magneto-entropy, and charge transport in NdAlGe.

A Model for Evaluating the Crystallinity Quality of Single Crystals Grown by the Floating Zone Technique (Crystal Research and Technology 1/2023)

Crystal Research and TechnologyVolume 58, Issue 1 2370001 Cover PictureFree Access A Model for Evaluating the Crystallinity Quality of Single Crystals Grown by the Floating Zone Technique (Crystal Research and Technology 1/2023) First published: 18 January 2023 https://doi.org/10.1002/crat.202370001AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract LiCoPO4 crystals have been grown by the floating zone method with different precursor materials, see article number 2200104 by Kunpeng Wang, Dongfeng Xue, and co-workers. The grown crystals were carefully characterized by polarized microscopic images, X-ray Laue back scattering technique, X-ray powder diffraction, and the EDX measurement. In order to optimize the crystal growth and quantitatively characterize the crystalline quality, the development factor (V) is proposed to determine the growth rate of the grains, while the orientation deviation factor (δ) is proposed for assessing the quality of the grown crystals. Volume58, Issue1January 20232370001 RelatedInformation

The Bridgman method of (BiAs)2 (TeSe)3 bulk single crystal growth by spontaneous nucleation

The Bi0.5As1.5Te2.98Se0.02 single crystal in 11 mm?80 mm size was grown using the Bridgman method. Energy dispersive spectrometry (EDS) analysis was used to determine the chemical composition of the studied samples, as well as for checking and confirming the homogeneity of the samples. Mobility, concentration of charge majority carriers and Hall coefficient of single crystal, were determined using a Hall Effec system based on the Van der Pauw method. Hall Effect was measured at room temperature with four ohmic contacts and at temperature of liquid nitrogen with silver contacts with an applied magnetic field strength of 0.37 T at different current intensities. The expected improvement in the mobility of obtained single crystal doped with this content of arsenic was not obtained.

Oxalic acid incorporated acetamide single crystal growth dynamics, characterization, NLO and antimicrobial activities via shock wave treatment

Shock waves are applied to non-linear optical materials, particularly organic materials, due to their fast responsein electro-optic switchesand high nonlinearefficiency. At room temperature, an acetamide-doped oxalic acid single crystal has been grown using the slow evaporation method among other crystal growth techniques. Single crystal oxac applies to shock waves in steps of 50 and 100 shock waves to the tail or the material properties without altering the original crystal system. The grown and shock wave treated crystals of OXAC were structurally identified by X-ray diffraction and Fourier transform infrared spectroscopy,UV–Visible and Photoluminescence spectral analysis, nonlinear optical activity (NLO) studies. The antimicrobial studies such as antibacterial and antifungal activities of the grown crystals of oxalic acid, OXAC and OXAC with 50 and 100 shocks were performed and the obtained results were discussed. From we declared results, we state that the post shock wave induced OXAC crystal is enhancing properties of NLO, antimicroibial studies relatively pre shock wave induced OXAC crystal and reflected in structural and optical studies.

Thermal Field of 6-inch Indium Phosphide Single Crystal Growth by Semi-sealed Czochralski Method

Thermal Field of 6-inch Indium Phosphide Single Crystal Growth by Semi-sealed Czochralski Method

Rapid single crystal growth via guest displacement from host-guest complexes.

The preparation of single crystals of sparingly soluble polycyclic aromatic compounds in MeCN is facilitated by solubilizing ionic host-guest complexation under otherwise poor solvent conditions. The guest is then crystallized within minutes through controlled guest displacement from the host via competitor equilibria, or over days through direct crystallization of the host-guest complex itself.

Single crystal growth of topological semimetals and magnetic topological materials

Topological materials have attracted much attention due to their novel physical properties. These materials can not only serve as a platform for studying the fundamental physics, but also demonstrate a significant potential application in electronics, and they are studied usually in two ways. One is to constantly explore new experimental phenomena and physical problems in existing topological materials, and the other is to predict and discover new topological material systems and carry out synthesis for further studies. In a word, high-quality crystals are very important for studying quantum oscillations, angle resolved photoemission spectra or scanning tunneling microscopy. In this work, the classifications and developments of topological materials, including topological insulators, topological semimetals, and magnetic topological materials, are introduced. As usually employed growth methods in growing topological materials, flux and vapour transport methods are introduced in detail. Other growth methods, such as Bridgman, float-zone, vapour deposition and molecular beam epitaxy methods, are also briefly mentioned. Then the details about the crystal growth of some typical topological materials, including topological insulators/semimetals, high Chern number chiral topological semimetals and magnetic topological materials, are elaborated. Meanwhile, the identification of crystal quality is also briefly introduced, including the analysis of crystal composition and structure, which are greatly important.

Single crystal growth of topological semimetals and magnetic topological materials

Topological materials have attracted much attention due to their novel physical properties. These materials can not only serve as a platform for studying the fundamental physics, but also demonstrate a significant potential application in electronics, and they are studied usually in two ways. One is to constantly explore new experimental phenomena and physical problems in existing topological materials, and the other is to predict and discover new topological material systems and carry out synthesis. In a word, high-quality crystals are very important for studying quantum oscillations, angle resolved photoemission spectra or scanning tunneling microscopy. In this work, the classifications and developments of topological materials, including topological insulators, topological semimetals, and magnetic topological materials, are introduced. As usually employed growth methods in growing topological materials, flux and vapour transport methods are introduced in detail. Other growth methods, such as Bridgman, float-zone, vapour deposition and molecular beam epitaxy methods, are also briefly mentioned. Then the details about the crystal growth of some typical topological materials, including topological insulators/semimetals, high Chern number chiral topological semimetals and magnetic topological materials, are elaborated. Meanwhile, the identification of crystal quality is also briefly introduced, including the analysis of crystal composition and structure, which are greatly important.

Single-crystal growth of layered metallic materials of TiTe2 based on a polytelluride flux method

TiTe2 single crystals were grown via a polytelluride flux method, which show a metallic behavior and low work function.

Study of Effect of Coil Movement on Growth Conditions of SiC Crystal.

SiC substrates have outstanding advantages over traditional materials in power device application, and are mainly prepared by a physical vapor transport method (PVT). Whether the PVT furnace works by resistance heating or induction heating, both face the problem of the deterioration of growth conditions during a long-term process. The relative position of the thermal field directly affects the crystal growth conditions, but the law of specific influence and the change in physical environment inside the thermal field have not been made sufficiently clear and lack systematic research. Therefore, SiC single crystal growth, with different directions and rates in the direction of movement of the heating module, was modeled using a simulation method, and the law of variation of the physical field, including heat flux, temperature, powder porosity and growth rate parameters under different schemes, was analyzed. The study indicates that the decay of raw materials is the primary reason why growth conditions cannot be maintained. The results verified that different coils' modes of movement have different effects on the improvement or adjustment of SiC crystals' growth conditions. Under the same temperature control conditions, the coils' movement rates of 200 μm/h, 0, -200 μm/h and -400 μm/h correspond to the average growth rates of 140, 152, 165 and 172 μm/h, respectively. The results show that downward displacement of the coils is beneficial in compensating for the deterioration of growth conditions, but it is easier to form convex surfaces and is not conducive to expanding diameter growth. This also verifies that the desired crystal growth state can be obtained by adjusting the position of the thermal field.

Epitaxial Growth of High-Quality Monolayer MoS2 Single Crystals on Low-Symmetry Vicinal Au(101) Facets with Different Miller Indices

Epitaxial growth of wafer-scale monolayer semiconducting transition metal dichalcogenide single crystals is essential for advancing their applications in next-generation transistors and highly integrated circuits. Several efforts have been made for the growth of monolayer MoS2 single crystals on high-symmetry Au(111) and sapphire substrates, while more prototype growth systems still need to be discovered for clarifying the internal mechanisms. Herein, we report the epitaxial growth of unidirectionally aligned monolayer MoS2 domains and single-crystal films on low-symmetry Au(101) vicinal facets via a facile chemical vapor deposition method. On-site scanning tunneling microscopy observations reveal the formation of a specific rectangular Moiré pattern along the [101̅] step edge of Au(101) and along its perpendicular direction. The perfect lattice constant matching of MoS2/Au(101) along the substrate high-symmetry directions (i.e., Au[101̅], Au [010]) as well as the step-edge-guiding effect are proposed to facilitate the robust epitaxy. Multiscale characterizations further confirm the domain-boundary-free feature of the monolayer MoS2 films merged by unidirectionally aligned monolayer domains. This work hereby puts forward a symmetry mismatched epitaxial system for the direct synthesis of monolayer MoS2 single crystals, which should deepen our understanding about the epitaxy of 2D layered materials and propel their applications in various fields.

Individual Effects of Flux Species as a Reaction Field on Coprecipitation Precursor toward the Design of Fine, Mono-Dispersed LiNi0.5Co0.2Mn0.3O2 Single Crystals

High-output lithium-ion batteries that have excellent high-rate capacity and durability are indispensable for high-energy devices. LiNi0.5Co0.2Mn0.3O2 (NCM523) is a representative active material and is typically used as a secondary particle. However, the practical use of NCM523 in high-output applications remains challenging, owing to insufficient capacity and cycle durability resulting from grain boundary resistance and cracks. Mono-disperse, fine particle characteristics are used for crystal designs for high-output performance. The single-crystal growth of NCM523 has been introduced using various methods; however, these methods primarily focused on NCM523 itself. Therefore, a guideline for crystal control, focusing on particle size and aggregation nature, is still necessary to achieve the optimal NCM523 design for an electrode structure. Precursor choice and reaction field design are important factors to consider to achieve mono-dispersed fine crystals. In this study, we focused on coprecipitation hydroxides as a precursor and molten flux as a reaction field and we studied the effect of fluxes on NCM523 crystal growth. We observed that flux species provide a unique contribution to the growth manner of NCM523. For example, borate-based flux disaggregated secondary particles, whereas chloride-based flux developed the crystal face in primary particles. Some fluxes provided mono-disperse NCM523 crystal particles with a size of less than 1 μm, which exhibited a 1st capacity over 110 mAh·g–1@5C and 100th capacity over 120 mAh·g–1@1C as high-output characteristics. The synergistic effect of the coprecipitate and flux on crystal growth was interpreted based on the growth manner observations. The results show that the size of NCM523 single crystals can be finely controlled in the submicron to several micron range. Coprecipitates can be made at many metal ions, including Mn, Co, and Ni; therefore, our suggested flux guideline for crystal design can be applied to other battery materials, such as NCM and LiCoO2. This insight contributes to the development of high-power battery electrodes based on particle-morphologic design.

Growth of rare-earth monopnictide DySb single crystal by novel self-flux method

A new method for the single crystal growth of rare-earth monopnictide DySb by self-flux technique is reported. Detailed structural, transport and magnetic characterisation of the crystal has been carried out by using X-ray diffraction (XRD), High resolution X-ray diffraction (HRXRD), resistivity and magnetisation measurements, respectively. The Rietveld refinement of powder XRD pattern reveals that the grown crystal is in single phase and crystallises in space group Fm3̄m (225) of rock- salt type crystal structure. The HRXRD and rocking curve analysis reveals the high-quality of the grown crystal. Temperature dependent resistivity and magnetisation measurements show a transition at 9.7 K from paramagnetic to antiferromagnetic state.

Solvation-Anionic Exchange Mechanism of Solvent Extraction: Enhanced U(VI) Uptake by Tetradentate Phenanthroline Ligands.

Phenanthroline diamides (L) demonstrated a unique ability to extract uranium from nitric acid solutions into a polar organic solvent forming complexes of 1:2 stoichiometry as tight ion pairs {[UO2LNO3]+[UO2(NO3)3]-} by a novel extraction mechanism, which is a combination of two already well-known mechanisms: solvation and ion-pair anion exchange. A UV-vis study was used to confirm the formation of such complexes directly in the organic phase. Moreover, chemical synthesis and single crystal growth were performed to confirm unambiguously the structure of the complexes in the solid state.

High Ionic Conduction and Polarity-Induced Piezoresponse in Layered Bimetallic Rb4Ag2BiBr9 Single Crystals

The emergence of lead-free metal-halide perovskites in modern-day energy research is primarily due to their competent semiconducting and optoelectronic properties, as well as their nontoxicity and improved stability in ambient operating conditions. However, a detailed understanding of ion transport dynamics and the relaxation behavior of these materials is still elusive. In this article, we report on the single-crystal (SC) growth of a bimetallic two-dimensional layered Rb4Ag2BiBr9 and explore its dielectric, piezoelectric, and ferroelectric properties. The dielectric attributes are investigated by studying the temperature-dependent complex impedance, complex electric modulus, and AC conductivity over an extensive frequency range from 4 Hz to 8 MHz. The role of grain and grain boundaries in the effective impedance is established using the Maxwell–Wagner equivalent circuit model from the Nyquist plots. The observed electric modulus spectra are studied using the Havriliak–Nigami and the Kohlrausch–Williams–Watts formalisms to understand the ionic transport and relaxation mechanisms in Rb4Ag2BiBr9. The DC conductivity and relaxation time show Arrhenius-like behavior with the inverse temperature validating the hopping motion of ions. The values of the activation energy required for ion hopping are calculated independently from the relaxation time, hopping frequency, and DC conductivity Arrhenius plots and are in good agreement with a value of 0.47 eV. The scaling of the temperature-dependent conductivity and electric modulus spectra into a single master curve demonstrates the congruence of the ionic conduction and the relaxation phenomena at different temperatures for Rb4Ag2BiBr9. This SC demonstrates decent thermal and ambient stability up to 500 °C and 12 months, respectively. The pristine orthorhombic Rb4Ag2BiBr9 SC shows a piezoelectric amplitude value of ∼564 pm at the maximum applied bias (±10 V), and a saturation polarization of ∼0.14 nC/cm2 estimated from the piezoelectric force microscopy and polarization hysteresis loop measurement, respectively. The ferroelectric and semiconducting attributes of this material can be harnessed for prospective applications as a thin film in designing mechanical energy harvesters as well as functional photoferroelectrics, such as optical switches and ferroelectric photovoltaics.

Rapid Growth of High-Quality Rutile TiO2 Single Crystals through a Laser Floating Zone Method

The rapid growth of rutile TiO2 single crystals through a laser floating zone (LFZ) method was demonstrated. LFZ has a higher power density, which is suitable for the growth of TiO2 crystals with a high melting point. By optimizing the crystal growth parameters, including the growth rate, gas atmosphere, and rotation rate, the crystals could achieve their largest size of φ 9 mm × 25 mm, with a growth cycle of 12 h, and no cracks appeared. The properties of the obtained crystals were close to those of the crystals grown using other schemes, with a whole transmission range of 0.41–6.56 μm, thermal expansion coefficient of 9.92 × 10−6/K, and laser damage threshold of 1.44 GW/cm2. The achieved results indicated that the crystals have high quality and good integrity when grown using LFZ and also imply a new choice for the rapid growth of rutile TiO2 single crystals.

Pterostilbene–Nicotinamide Cocrystal: A Case Report of Single Cocrystals Grown from Melt Microdroplets

Screening and single-crystal growth of cocrystals is a time-consuming process, typically performed by solution crystallization. Here we reported a case that a single pterostilbene–nicotinamide cocrystal was efficiently cultivated from melt within 30 min, resulting in successful structure elucidation. This new cocrystal was discovered from melts and can be prepared on a gram scale within 10 min by simply seeding melts at 80 °C. This work demonstrates the possibility of growing single cocrystal from the melts and highlights the high efficiency of melt crystallization in research of pterostilbene–nicotinamide cocrystals.