Solid-state Growth Research Articles

Structural Properties of Thermoluminescence Dosimeter Materials, Preparation, Application, and Adaptability: A Systematic Review

Thermoluminescence dosimeters (TLDs) are widely used in radiation dosimetry due to their excellent properties, such as high sensitivity, small size, and ability to measure low doses of radiation. This review focuses on the structural properties of TLD materials, as well as their preparation, application, and adaptability. The review covers the various types of TLD materials, crystal structure, and properties, including energy response and fading characteristics. The different methods used to prepare TLD materials, such as solid-state synthesis, sol-gel synthesis, and solution growth methods, are discussed in detail. The review also includes a detailed discussion of the various applications of TLDs, including medical, environmental, and industrial radiation dosimetry. Extensive information on TLD is reviewed, and the TL characteristics that have a noticeable impact on the TL dosimetry potential for human and other purpose utilisation, such as mineral, oil, and gas resource investigation, can be done using natural and artificial TL signals. Information on TL measurement process requirements and the TL characteristics that have a noticeable impact on a compound TL dosimetry potential are also addressed. Finally, the review concludes by highlighting the adaptability of TLD materials to different dosimetry applications and their potential use in the future.

Enhanced high-temperature ductility without strength drop in a lean Co Ni-based superalloy

The conventional Ni-based IN738LC superalloy series are typically hardened by a fine distribution of closely spaced fine and coarse Ni3(Al, Ti)-type L12 ordered γ' precipitates, which is formed by solid-state nucleation and growth in the disordered γ matrix. However, outstanding high-temperature mechanical performance requires a high amount (∼9 wt%) of Co, which is the alloy's most expensive adding element. Here, we report a compositionally modified IN738LC alloy with a 50% reduction in Co content and a 20% increase in comparatively cheaper Mo content. This compositional modification caused more γ' precipitates with uniform distribution than those in the conventional counterpart subjected to the same heat treatments. The modified superalloy showed a twofold increase in high-temperature (750 °C) tensile elongation while maintaining the conventional one's strength (∼1.1 GPa) at the temperature. This remarkable ductility gain, while no loss in strength, was predominantly attributed to a transition in the high-temperature deformation mechanism, i.e., from multiple intersecting slip bands-indued stress localization for the conventional IN738LC alloy to unidirectional microtwins for the modified IN738LC material. More Mo and less Co contents could drive more coherent γ' precipitates in the annealed state and the high density of microtwins in the deformed state, resulting in stress delocalization and enhanced ductility at comparable strength. The findings of this study have significant implications for the development of cost-effective, strong, and ductile superalloys for high-temperature applications.

Graphene controlled solid-state growth of oxygen vacancies riched V2O5 catalyst to highly activate Fenton-like reaction

Fenton-like process based on metal oxide presents one of the most hoping strategies to generate reactive oxygen species to treat refractory pollutants. The introduction of oxygen vacancies (OVs) can enhance the catalytic performance of metal oxides in Fenton-like reaction. In this paper, a one-step all solid-state synthesis strategy is proposed to induce oxygen defects in V2O5, which uses graphene to engineer the crystallization process of V-based crystals. Such approach employs graphene as a solid-catalyst to promote growth of V-based crystals owing to the ions-π interactions between graphene and VCl3. The electron-donor OVs in V2O5@graphene can not only active H2O2 for the •OH generation, but also accelerate the reduction of V5+ and V4+, thereby ensuring defective V2O5@graphene/H2O2 system is 14.3, 28.2, and 17.3 times higher than that of graphene/H2O2, pure V2O5/H2O2 and graphene+V2O5/H2O2 (mechanical mixed system), respectively. Our study provides a novel synthetic strategy to design and prepare OVs-riched transition metal catalysts for developing advanced oxidation technologies toward higher sustainability and practicality.

Scale-bridging phase-field approach for nucleation and microstructure evolution applied to the β to α phase transformation in pure titanium

Modeling concurrent nucleation and growth in the phase-field framework on experimentally relevant length scales remains a significant challenge due to spatial resolution and driving force limitations. This work proposes a modeling framework that overcomes these challenges by integrating the explicit nucleation method within the recently developed high-driving force phase-field model to investigate the influence of the cooling rate on solid-state nucleation and growth. The model accurately captures the growth behavior of individual nuclei across varying length scales, and allows efficient one grid point nucleation without modifying the high driving force equation. To accommodate nanoscale nucleation within a mesoscale phase-field framework, the model incorporates an analytical subscale step accounting for critical nucleus growth to one grid point. The model was applied to the β to α transformation in extra pure titanium, for which a material-specific input parameter study was performed. Simulation results were compared to experimental results on the cooling rate dependence of transformation temperatures and mean grain sizes obtained through an Electron Backscatter Diffraction analysis of furnace-, air-, and water-cooled samples. The model's significance lies in extending the phase-field method's applicability to simulate nucleation on much larger length-scales than previously achievable, bridging the gap between simulation and experimental length-scales.

Synthesis, sintering, and grain growth kinetics of Hf6Ta2O17

A systematic study of the solid-state synthesis, pressureless sintering, and grain growth kinetics of Hf6Ta2O17 is presented. The ideal conditions for solids-state synthesis of Hf6Ta2O17 powder with minimal particle necking was 1250 °C for 2 h in air. The resultant powder has an average particle size of 210 ± 70 nm. The combined synthesis and ball-milling procedure produces highly sinterable Hf6Ta2O17 powder, achieving > 97 % of theoretical density after pressureless sintering at 1600 °C for 2 h in air. The grain growth mechanism was sensitive to processing conditions, appearing to be primarily driven by surface diffusion below 1600 °C and grain boundary diffusion above 1650 °C. The respective activation energies for grain growth were found to be QS = 659 ± 79 kJ mol−1 and QGB = 478 ± 63 kJ mol−1.

Solid-state self-catalyzed growth of N-doped carbon tentacles on an M(Fe, Co)Se surface for rechargeable Zn-air batteries.

A scalable and facile solid-catalyzed growth approach is reported to integrate N-doped carbon tentacles with metal selenide nanoparticles, showing great potential for mass production of non-precious metal catalysts for rechargeable Zn-air batteries.

The void formation behaviors in working solid-state Li metal batteries.

The fundamental understanding of the elusive evolution behavior of the buried solid-solid interfaces is the major barrier to exploring solid-state electrochemical devices. Here, we uncover the interfacial void evolution principles in solid-state batteries, build a solid-state void nucleation and growth model, and make an analogy with the bubble formation in liquid phases. In solid-state lithium metal batteries, the lithium stripping-induced interfacial void formation determines the morphological instabilities that result in battery failure. The void-induced contact loss processes are quantified in a phase diagram under wide current densities ranging from 1.0 to 10.0 milliamperes per square centimeter by rational electrochemistry calculations. The in situ-visualized morphological evolutions reveal the microscopic features of void defects under different stripping circumstances. The electrochemical-morphological relationship helps to elucidate the current density- and areal capacity-dependent void nucleation and growth mechanisms, which affords fresh insights on understanding and designing solid-solid interfaces for advanced solid-state batteries.

Laser-Induced Crystallization of Copper Oxide Thin Films: A Comparison between Gaussian and Chevron Beam Profiles.

The use of a laser with a Gaussian-beam profile is frequently adopted in attempts of crystallizing nonsingle-crystal thin films; however, it merely results in the formation of polycrystal thin films. In this paper, selective area crystallization of nonsingle-crystal copper(II) oxide (CuO) is described. The crystallization is induced by laser, laser-induced crystallization, with a beam profile in the shape of a chevron. The crystallization is verified by the exhibition of a transition from a nonsingle-crystal phase consisting of small (∼100 nm × 100 nm) grains of CuO to a single-crystal phase of copper(I) oxide (Cu2O). The transition is identified by electron back scattering diffraction and Raman spectroscopy, which clearly suggests that a single-crystal domain of Cu2O with a size as large as 5 μm × 1 mm develops. The transition may embrace several distinctive scenarios such as a large number of crystallites that densely form grow independently and merge, and simultaneously, solid-state growth that takes place as the merging proceeds reduce the number of grain boundaries and/or a small number of selected crystallites that sparsely form grow laterally, naturally limiting the number of grain boundaries. The volume fraction of the single-crystal domain prepared under the optimized conditions─the ratio of the volume of the single-crystal domain to that of the total volume within which energy carried by the laser is deposited─is estimated to be 32%. Provided these experimental findings, a theoretical assessment based on a cellular automaton model, with the behaviors of localized recrystallization and stochastic nucleation, is developed. The theoretical assessment can qualitatively describe the laser beam geometry-dependence of vital observable features (e.g., size and gross geometry of grains) in the laser-induced crystallization. The theoretical assessment predicts that differences in resulting crystallinity, either single-crystal or polycrystal, primarily depend on a geometrical profile with which melting of nonsingle-crystal regions takes place along the laser scan direction; concave-trailing profiles yield larger grains, which lead to a single crystal, while convex-trailing profiles result in smaller grains, which lead to a polycrystal, casting light on the fundamental question Why does a chevron-beam profile succeed in producing a single crystal while a Gaussian-beam profile fails?

The underlying role of sodium tripolyphosphate on the cementitious mechanism of calcium carbonate binder

Calcium carbonate binder is well-known to reduce the carbon footprint and brings great economic and environmental benefits. However, the cementitious mechanism is unclear due to raw material diversity. We prepare calcium carbonate crystalline polymorphs-vaterite and calcite in the presence of sodium tripolyphosphate (STPP), and the cementitious mechanism is revealed. Herein, the optimal colloidal structure with vaterite as the binding phase is obtained at 5% STPP and the 1d compressive strength reaches 16.99 MPa. The cementitious property can be attributed to the crystallization transformation of amorphous calcium carbonate (ACC) and the electrostatic attraction of particles. In the cementitious process, the effect of STPP on the polymorph selection is determined by STPP contents. At low contents (＜5%), STPP is more effective in inhibiting the nucleation and growth of calcite than vaterite. At high contents (＞5%), calcite is entirely inhibited while the formation of vaterite takes place on the surface of bulk ACC through the coupling mechanism of dissolution-recrystallization and solid-state growth. These results shed light on the function of STPP during calcium carbonate biomineralization and the cementitious mechanism can help for preparing low-carbon calcium carbonate binder.

Ultra-low shrinkage and high-strength porous TiB/TiB2 ceramics via low temperature in-situ reaction sintering combined with the freeze-drying method

Ultra-low shrinkage porous TiB 2 -based ceramics reinforced by the TiB whiskers are firstly fabricated through the in-situ reaction between TiB 2 and Ti at a low temperature (1450 °C). The growth of TiB whiskers with a high aspect ratio at pore channels is achieved through a vapor-solid growth mechanism, while low aspect ratio TiB whiskers at pore walls are dominated by a solid-state reaction diffusion growth, forming bimodal distribution whiskers in porous TiB 2 -based ceramics. The overlapping TiB whiskers with low-speed growth at particle contact points can significantly inhibit the shrinkage and improve the strength of porous TiB 2 -based ceramics. When the solid content is fixed at 20 vol% and target TiB content changes from 0 to 80 vol%, the porous ceramics show slight sintering shrinkage (from 1.1 to 4.7%) and high porosity (from 79.3 to 73.7%) while keeping high compressive strength of 1.8–18.2 MPa, which is higher than most reported porous ceramics at the same porosity.

Solubility Measurements of NaTaO3 in Molten Na2MO4 (M = Mo, W, and S) and Growth of Milli-Order Crystals at High Frequency.

Sodium tantalate (NaTaO3) is an attractive functional material for photocatalysis. To understand its physical properties, significant efforts for milli-sized single-crystal growth of NaTaO3 have been made. However, the growth was difficult due to the smaller size in solid-state growth or probable decomposition and melting in melt growth. Recently, we grew milli-order NaTaO3 single crystals in Na2MoO4 flux. However, the reproducibility of the growth was not sufficient and hindered the stable supply of the crystal for physicochemical evaluations and further growth. The poor reproducibility was assumed to be due to the inhomogeneous, unstable growth field in response to the external atmosphere provided by nonoptimal experimental conditions. A saturated solution is considered the most suitable crystal growth field because it has the highest solubility and facilitates crystal growth with suppressed nucleation. Since supersaturation is the driving force for crystal growth, we considered that large crystals could be obtained with high frequency if growth could be controlled in the region where solubility changes rapidly. To compile a guideline for crystal growth under the control of supersaturation, the solubility of NaTaO3 in Na-based fluxes, including Na2MoO4, was studied. Using NaTaO3 molding pellets immersed in molten flux, the solubility curve for NaTaO3 was successfully measured. Based on the solubility, the optimal experimental conditions, that is, the heating temperature, the slow-cooling section, and the amount of flux as a solvent, were determined. Finally, we demonstrated the growth of NaTaO3 in Na2MoO4 flux and achieved milli-order crystals with high frequency. Our findings regarding the solubility of NaTaO3 in molten flux may assist in the stable supply of milli-order single crystals for material evaluation and larger crystal growth.

Electron Probe Microanalysis and Microscopy of Polishing-Exposed Solid-Phase Mineral Inclusions in Fuxian Kimberlite Diamonds

Solid-phase mineral inclusions in diamond (1–3 mm in diameter) from the No. 50 kimberlite diatreme of Liaoning Province, China, were exposed by polishing. A variety of silicate, carbonate and sulfide inclusions were recovered in the diamond. The common solid-phase inclusions are olivine, chromite, garnet and orthopyroxene; the rare phases include Ca carbonate, magnesite, dolomite, norsethite, pyrrhotite, pentlandite, troilite, a member of the linnaeite group, an unknown hydrous magnesium silicate and an Fe-rich phase. Abundance and composition of the solid-phase inclusions in diamond indicate that they belong to the peridotitic suite and are mainly harzburgitic. No eclogitic mineral inclusions were found in the diamond. The slightly lower Mg # of the olivine inclusions (peak at 93) than that of harzburgitic olivine inclusions worldwide (Mg # peak at 94), the higher Ni content (0.25–0.45 wt. %) of the olivine inclusions than those of olivine inclusions worldwide (0.30–0.40 wt. %), the higher Ti contents (up to 0.79 wt. %) in some chromite inclusions in diamond than those in chromite inclusions worldwide, the existence of carbonate inclusions in diamond, and the possible presence of hydrous silicate phases in diamond all indicate a metasomatic enrichment event in the source region of diamond beneath the North China craton, suggesting that the diamond probably formed by solid-state growth under metasomatic conditions with the presence of a fluid. Solid-state growth of diamond is also supported by abundant graphite inclusions in the diamond. Sulfide inclusions in diamond often coexist with chromite and olivine or are rich in Ni content, indicating that the sulfide inclusions belong to the peridotitic suite. From the chemical compositions, most sulfide inclusions in diamond from the No. 50 kimberlite were probably trapped as monosulfide crystals, although some may have been entrapped as melts.

Solid-state single-crystal growth of YAG and Nd: YAG by spark plasma sintering

• Growth of YAG and Nd:YAG single crystals achieved during the spark plasma sintering. • Porosity of the single crystals reduced due to the application of external pressure. • High Nd 3+ doping had a positive effect on the single-crystal conversion kinetics. Recent studies have shown that many challenges encountered in conventional single crystal growth methods, including high production costs, can be overcome by using the solid-state single-crystal growth (SSCG) approach, which has been recognized as a simple and cost-effective alternative for obtaining single crystals. In this work, Y 3 Al 5 O 12 (YAG) and Nd 3+ -doped YAG (Nd:YAG) single crystals were grown via the SSCG method using spark plasma sintering (SPS). The growth of single crystals was initiated at the surface of (110) YAG single-crystal seeds embedded inside YAG and Nd:YAG powder beds, and this growth continued as the surrounding polycrystalline matrix was converted into a single crystal. The application of external pressure during the SPS process has been found beneficial for reducing the porosity of the grown single crystals. Moreover, high Nd 3+ doping levels had a positive effect on the conversion kinetics, with a growth rate of almost 50 µm/h, which increased the driving force for single-crystal growth through the solute drag effect. EDS elemental mapping and line scans confirmed the compositional uniformity of the grown single crystals, while EBSD images verified their crystallization in the (110) direction. The obtained results confirm the strong potential of the SSCG technique coupled with SPS for the growth of undoped and highly doped YAG single crystals with excellent quality.

On the solid-state dendritic growth of [formula omitted] carbide at interfaces in an austenitic system

Solid-state growth of M7C3 carbide at different interfaces in an austenitic Ni–Cr–Fe alloy (Alloy 600) was studied in-situ by high temperature confocal laser scanning microscopy during continuous cooling from 1140 °C. The carbide develops a dendritic morphology and grows laterally across the free surface via a diffusion-assisted mechanism. Primary dendrite arms can extend beyond 100 μm, with some dendrites also developing secondary arms with spacing approximately 3.0 μm. By using focused ion beam tomography, some of the surface carbides are found to be directly connected to dendritic carbide at grain boundaries in the bulk confirming they originated from the same nucleus. Matrix deformation is induced in the vicinity of a carbide during growth. This work provides significant insight into the important topic of carbide development by a rare combination of both in-situ microscopy and a 3D tomographic technique; the new knowledge discovered is expected to apply to other austenitic systems.

α phase growth and branching in titanium alloys

ABSTRACT The morphology and spatial distribution of alpha (α) precipitates have been mapped as a function of Mo content in Ti-Mo binary alloys employing a combinatorial approach. Heat-treatments were carried out on compositionally graded Ti-xMo samples processed using a rapid throughput laser engineered net shape (LENS) process. The composition space spans 1.5 at% to 6 at% Mo with ageing at 750°C, 650°C and 600°C following a β solution treatment. Three distinct regimes of α morphology and distribution were observed. These are colony-dominated microstructures originating from grain boundary α allotriomorphs, bundles of intragranular α laths, and homogeneously distributed individual fine-scale α laths. Branching of the α precipitates was observed in all these domains in a manner reminiscent of solid-state dendritic growth. The phenomenon is particularly apparent at low volume fractions of α. Similar features are present in a wide variety of alloy compositions. 3-dimensional features of such branched structures have been analysed. Simulation of the branching process by phase field methods incorporating anisotropy in the α/β interface energy and elasticity suggests that it can be initiated at growth ledges present at broad faces of the α laths, driven by the enhancement of the diffusion flux at these steps. The dependence of branching on various parameters such as supersaturation and diffusivity, and microstructural features like ledge height and distribution and the presence of adjacent α variants has been evaluated.

Organic Crystal Growth: Directly from Amorphous Solid Powder to Single Crystals.

Preparation of organic crystals mainly depends on solution-deposition, sublimation, and melt-deposition techniques. Solid-state growth methods are generally not suitable for organic crystal growth due to the unprocurable mass transfer. Herein, we report two pyridine-substituted fluorenone compounds with extraordinary crystal-growth capacity, and these compounds can directly and quickly form single crystals from their amorphous solid powder by heating under antisolvent-assistance conditions. The novel experimental phenomenon and crystal growth mechanism were investigated in depth. The results indicate that multiple intermolecular hydrogen-bonding sites and planar aromatic structure (prone to π-π interactions) of these molecules dominate the mass transfer during crystal growth by providing enough energy. This discovery enhances our knowledge of solid-state methods for single-crystal growth.

Enhancement of pyroelectricity in Mn-doped (011) 71Pb(Mg1/3Nb2/3)O3–6PbZrO3–23PbTiO3 single crystals

Single crystals of 71PMN-6PZ-23PT [71Pb(Mg1/3Nb2/3)O3-6PbZrO3-23PbTiO3] oriented along the thickness direction (011) with and without Mn doping were grown by a solid-state single-crystal growth method, and pyroelectric properties of the crystals were investigated. Though the pyroelectric coefficient of a Mn doped crystal is not significantly higher than the un-doped one at room temperature (RT), a large enhancement was observed after 0.7 mol. % Mn doping at high temperatures (>100 °C). Furthermore, the FoMs for practical applications at RT, the Mn doped crystal showed large enhancement as compared to the un-doped one. The presented single crystals also yielded excellent figure of merit (FoM) values for pyroelectricity: Fi, Fv, and FD were 3.5 × 10−10 m V−1, 0.02 m2 C−1, and 2.68 × 10−5 Pa−1/2, respectively, at RT. The large pyroelectric response in the Mn-doped single crystal is attributed to the large ferroelectric polarization and low dielectric constant and dielectric loss. The demonstrated pyroelectric response in the Mn-doped 71PMN-6PZ-23PT single crystal shows that it exhibits excellent potential for various thermal sensor applications.

Covalently binding ultrafine MoS2 particles to N, S co-doped carbon renders excellent Na storage performances

MoS2 has attracted much interest for the potential application in sodium-ion batteries (SIBs) anodes because of the high theoretical capacity and electrochemical activity with Na. However, poor electrochemical performance caused by severe volume variations during the charge/discharge processes limits its practical application. Herein, we present an elaborately designed architecture comprising ultrafine MoS2 nanoparticles covalently bonded to N, S co-doped carbon (MoS2/NSC) via an in situ solid-state growth process, which displays high-capacity Na storage, fast sodiation/desodiation kinetics, and substantially mitigated volume fluctuations. As a consequence, MoS2/NSC delivers outstanding Na storage performances including a high reversible capacity of 340 mA h g−1 at 100 mA g−1 and a rate capacity of 208 mA h g−1 at 2000 mA g−1. Further assembling with a Na3V2(PO4)3/C cathode, the full-cell delivers a specific capacity of 238 mA h g−1 after 80 cycles at 50 mA g−1, demonstrating the great potential of our MoS2/NSC electrode. Density function theory calculations manifest that NSC not only presents strong binding to MoS2 but also significantly decreases the Na ion diffusion energy barrier, thus leading to robust structure stability and fast electrode kinetics. This study may open a new and efficient avenue for developing advanced MoS2 anodes for SIBs.

Grain growth in sintering: A discrete element model on large packings

Sintering is a high temperature process used for ceramic or metallic powder consolidation that consists of concurrent densification and grain growth. This work presents a coupled solid-state sintering and grain growth model capable of studying large packings of particles within the Discrete Element Method (DEM) framework. The approach uses a refinement for large particle size ratios of previously established contact laws to model shrinkage. In addition, mass transfer between neighboring particles is implemented to model grain growth by surface diffusion and grain-boundary migration. The model assumptions are valid for initial and intermediate stage sintering. The model is validated on a two-particle system by comparing neck and particle size evolutions with those obtained by phase-field and meshed-based methods. Simulations on large packings (up to 400 000 particles) with particle size distributions originating from experiments are performed. The results of these simulations using physical data from the literature are compared to experimental data with good accordance of the key features of the microstructure evolution (densification kinetics, grain size-density trajectory, evolution of the mean grain size and of the size distribution). The simulations show that even at an early stage of sintering, hardly detectable grain growth actually affects the sintering kinetics to a non-negligible extent and that the realism of DEM simulations of sintering is improved when grain growth is considered. Taking advantage of the possibility to simulate large packings, the model elucidates the influence of the initial particle size distribution on the grain growth kinetics.

Enhanced protein and amino acids of corn-ethanol co-product by Mucor indicus and Rhizopus oryzae.

Upcycle of co-products from corn-ethanol plant into protein-rich animal feed with balanced key amino acids via solid-state fermentation is a promising approach to economically support both biofuel and animal feed industries. However, there are multiple types of solid-state fermentation microorganisms and growth conditions that have not been tested. In this study, Mucor indicus and Rhizopus oryzae were used to ferment corn-based wet distiller's grains with solubles (WDGS). The effects of fermentation conditions (temperature, agitation, and moisture) and supplementations (extraneous carbon and nitrogen sources) were evaluated on protein production and amino acids profiles before and after fermentation. The study established best fermentation conditions (23°C, static incubation for 4days at 70% initial moisture content) to improve protein content for both R. oryzae and M. indicus. Moreover, urea supplied to R. oryzae and M. indicus improved protein concentration by 35 and 38%, and total amino acids content by 28 and 18%, respectively. The amount of 693.1 and 451.8mg of additional total amino acids including 262.8 and 227.7mg of key amino acids (lysine, methionine, tryptophan, and arginine) was synthesized by R. oryzae and M. indicus, respectively, per supply of 536mg urea in 25g of WDGS. This study demonstrated the feasibility of urea as a low-cost nitrogen source for amino acid biosynthesis in fungal fermentation of WDGS, which could contribute to the increasing demand for high-value monogastric animal feed.