Crystal Nucleation Rate Research Articles

Phosphorus recovery via struvite crystallization in batch and fluidized-bed reactors: Roles of microplastics and dissolved organic matter

Struvite crystallization, a promising technology for nutrient recovery from wastewater, is facing considerable challenges due to the presence of emerging contaminants such as microplastics (MPs) ubiquitously found in wastewater. Here, we investigate the roles of MPs and humic acid (HA) in struvite crystallization in batch and fluidized-bed reactors (FBRs) using synthetic and real wastewater with a Mg:N:P molar ratio of 1:3:(1–1.3) at an initial pH of 11. Batch reactor (BR) experiment results show that MPs expedited the nucleation and growth rates of struvite (e.g., the rate of crystal growth in the presence of 30 mg L−1 of polyethylene terephthalate (PET) was 1.43 times higher than that in the blank system), while HA hindered the formation of struvite. X-ray diffraction and the Rietveld refinement analysis revealed that the presence of MPs and HA can result in significant changes in phase compositions of the reclaimed precipitates, with over 80 % purity of struvite found in the precipitates from suspensions in the presence of 30 mg L−1 of MPs. Further characterizations demonstrated that MPs act as seeds of struvite nucleation, spurring the formation of well-defined struvite, while HA favors the formation of newberyite rather than struvite in both reactors. These findings highlight the need for a more comprehensive understanding of the interactions between emerging contaminants and struvite crystallization processes to optimize nutrient recovery strategies for mitigating their adverse impact on the quality and yield of struvite-based fertilizers. Environmental ImplicationThe presence of microplastics in wastewater poses a significant challenge to struvite crystallization for nutrient recovery, as it accelerates nucleation and growth rates of struvite crystals. This can lead to changes in the phase compositions of the reclaimed precipitates, with implications for the quality and yield of struvite-based fertilizers. Additionally, the presence of humic acid hinders the formation of struvite, favoring the formation of other minerals like newberyite. Understanding the interactions between emerging contaminants and struvite crystallization processes is crucial for optimizing nutrient recovery strategies and mitigating the environmental impact of these contaminants on water quality and struvite-based fertilizers.

The dual action of N2 on morphology regulation and mass-transfer acceleration of CO2 hydrate film

The morphology characteristics of CH4, CO2 and CO2+N2 hydrate film forming on the suspending gas bubbles are studied using microscopic visual method at supercooling conditions from 1.0 to 3.0 K. The hydrate film vertical growth rate and thickness along the planar gas-water interface are measured to study the hydrate formation kinetics and mass transfer process. Adding N2 in the gas mixture plays the same role as lowering the supercooling conditions, both retarding the crystal nucleation and growth rates, which results in larger single crystal size and rough hydrate morphology. N2 in the gas mixture helps to delay the secondary nucleation on the hydrate film, which is beneficial to maintain the pore-throat structure and enhance the mass transfer. The vertical growth rate of hydrate film mainly depends on the supercooling conditions and gas compositions but has weak dependence with the experimental temperature and pressure. Under the same gas composition condition, the final film thickness shows a linear relationship with the supercooling conditions. The mass transfer coefficient of CH4 molecules in hydrates ranges from 4.54 to 7.54×10–8 mol·cm–2·s–1·MPa–1. The maximum mass transfer coefficient for CO2+N2 hydrate occurs at the composition of 60% CO2+40% N2, which is 3.98×10–8 mol·cm–2·s–1·MPa–1.

Self‐Regulated Growth of Large‐Grain Sb2S3 Thin Films for High‐Efficiency Solar Cells

AbstractAntimony sulfide (Sb2S3) has attracted extensive attention due to its excellent photoelectric characteristics, including a high absorption coefficient (α > 104 cm−1) and a suitable bandgap (≈1.7 eV). However, due to its Q1D (quasi‐1D) structure, numerous deep‐level defects are identified in the Sb2S3 film, limiting the device's performance, and necessitating more efforts to overcome this situation. In this context, an ethanol solvent‐assisted chemical bath deposition (S‐CBD) strategy, a novel high‐quality thin film manufacturing technique is presented that modifies the supersaturation of the precursor solution by varying the boiling point and solvent polarity. This approach enables the effective regulation of the correlation between the crystal nucleation and growth rates, resulting in Sb2S3 films with large grains (≈4.25 µm, 37.5% ethanol), excellent crystallinity, well‐oriented structures (TC(211)/TC(020) = 2.39), low defect density, and prolonged carrier lifetimes (τAve ≈ 12.1 ns). Consequently, the final Sb2S3‐based solar device (FTO/CdS/Sb2S3/Spiro‐OMeTAD/Au) shows significant improvements in both FF (61.63%) and JSC (17.61 mA cm−2), yielding an excellent power conversion efficiency (PCE) of 7.84%. This research gives particular insights into the growth mechanism of high‐quality Sb2S3 thin films by CBD method as well as a potential route for enhancing Sb2S3 solar cell performance.

Rapid, low-cost exploration of nucleation rates in l-glutamic acid crystallization in pure media and the presence of polymers through novel parallel experimentation

Crystal nucleation is crucial in various fields of science and technology, ranging from materials synthesis to pharmaceutical production. Our research aims to determine the nucleation rates from parallel induction time measurement experiments followed by low-cost external bulk video imaging. Stirred conditions are applied, making our results industry-relevant where the crystallizers are also mixed. The L-Glutamic Acid-water system (L-GA/water) is used as a surrogate. The study is conducted through a series of parallel, small-scale stirred experiments that explore the effects of supersaturation, temperature, and polymer additives on nucleation rates. The methodology involves careful data collection through controlled experimental setup and analysis of induction time distributions that the stochastic nature of nucleation explains the induction time distribution. The discussion section interprets the findings within the context of the research question, highlighting the implications of varying temperature and supersaturation levels as two experimental parameters and polymers on crystal nucleation rates. The specific parameters of supersaturation and temperature dependencies are in the range of those reported in the literature, which validated the developed rapid nucleation rate measurement platform. Stepping outside of these established measurements, analyzing the influence of polymers with high potential in controlling particle size, shape, and polymorphism was touched as well. As an unexpected result, the nucleation rates appeared to depend not only on the chemical structure and amount of the polymer but also on the polymer solution preparation method. The remarkable influence of polymers on nucleation rates was shown that cannot be explained with the solubility altering effect of the polymers alone.

Single‐element amorphous metals

AbstractTo unveil the nature of amorphous states, single‐element amorphous metals have been the perfect research subject due to the simplest composition. However, the extreme crystal nucleation and growth rate in single‐element metal make the synthesis of single‐element amorphous metals seemingly impossible in the past. Fortunately, benefited by several delicate synthetic strategies developed recently, the single‐element amorphous metals have been successfully demonstrated. This review aims to provide a systematic overview of the synthesis of single‐element amorphous metals covering the challenges in physics and recent achievements. In addition, current understanding of the atomic and electronic structures of single‐element amorphous metal has also been included. Finally, the challenges that worth further investigation are discussed. By identifying the potential avenues for further exploration, this review aims to contribute valuable insights that will propel the cognition of single‐element amorphous metals.

Influence of Organic Impurities on Fractional Crystallization of NaCl and Na2SO4 from High-Salinity Coal Chemical Wastewater: Thermodynamics and Nucleation Kinetics Analysis.

It is a valid path to realize the zero discharge of coal chemical wastewater by using the fractional crystallization method to recycle the miscellaneous salt in high-salinity wastewater. In this study, the thermodynamics and nucleation kinetics of sodium chloride (NaCl) and sodium sulfate (Na2SO4) crystallization in coal chemical wastewater were systematically studied. Through analyses of solubility, metastable zone width, and induction period, it was found that the impurity dimethoxymethane would increase the solid-liquid interface energy and critical crystal size during the nucleation of Na2SO4. Ternary phase diagrams of the pseudo-ternary Na2SO4-NaCl-H2O systems in simulated wastewater were plotted in the temperature range of 303.15 to 333.15 K, indicating that a co-ionization effect existed between NaCl and Na2SO4, and NaCl had a strong salting out effect on Na2SO4. Finally, the nucleation rate and growth rate of Na2SO4 crystals under simulated wastewater conditions were determined by the intermittent dynamic method, and the crystallization kinetic models of Na2SO4 were established. The crystallization nucleation of Na2SO4 crystals was found to be secondary nucleation controlled by surface reactions. The basic theoretical research of crystallization in this study is expected to fundamentally promote the application of fractional crystallization to realize the resource utilization of high-salinity wastewater in the coal chemical industry.

Engineering porosity of MIL-101(Cr) using solvation effect

Toluene, a kind of volatile organic compounds (VOCs), serves as a vital constituent of PM2.5 and acts as a notable precursor to ozone. To improve the adsorption performance of adsorbents for toluene, MIL-101(Cr)-XmM with high porosity were synthesized using an in-situ growth restriction strategy. This research reveals that the solvation effect influences the rate of crystal nucleation and growth, leading to variations in the ratio of micropores to mesopores and overall porosity in MIL-101(Cr)-XmM. The high porosity of MIL-101(Cr)-1.6 mM facilitates a higher diffusion rate of particles and exposes a greater number of alkaline sites. Consequently, the adsorption performance of MIL-101(Cr)-1.6 mM for toluene demonstrates a remarkable 240% improvement compared to that of MIL-101(Cr)-1.2 mM. Molecular simulations unveils the impact of adsorption temperature, demonstrating the crucial role of van der Waals interactions in the adsorption of toluene, with a noteworthy inhibition of van der Waals interactions observed upon heating. Density functional theory(DFT) simulations show that toluene molecules tend to preferentially adsorb near the benzene ring of the ligand, primarily due to π-π stacking interactions. Simultaneously, the electrophilic channel with greater porosity can gather more nucleophilic groups, thereby enhancing the adsorption performance of toluene.

Homogeneous Organic Crystal Nucleation Rates in Solution from the Perspective of Chemical Reaction Kinetics

It is demonstrated for 11 different combinations of organic solutes and solvents that the supersaturation dependence of homogeneous organic crystal nucleation rates from solution can be predicted from the solubility, bar a single empirical rate constant, when it is assumed that nucleation takes place in reversible aggregates of solvated solutes formed in supersaturated solutions. Reversible solute aggregation represents natural solute density fluctuations that take place in any solute/solvent system. For thermodynamically ideal solutions, the steady state size distribution, and thus the population of reversible aggregates in supersaturated solution, can be predicted quantitatively from the overall solute concentration by a simple mathematical expression. Supersaturation creates an excess of reversible aggregates with sizes exceeding that of the largest aggregate in saturated solution. It is shown that the number of these excess aggregates is proportional to experimental homogeneous nucleation rates, suggesting a rate equation for homogeneous nucleation that has only one empirical parameter, namely, a rate constant specific to the solute/solvent combination. This rate constant can be determined from standard nucleation rate data. The system-specificity of homogeneous nucleation rates thus appears to be encoded solely in a rate constant for the transformation of the large excess aggregates into crystal nuclei. The driving force for triggering nucleation events in these aggregates is likely the extremely high local supersaturation, which provides the conditions for spatiotemporally aligned bond-breaking (e.g., de-solvation) and bond-forming (e.g., solute–solute bonding) events that create stable crystal nuclei. The possible influence of heterogeneous nucleation by solid impurities is considered.

Isothermal and nonisothermal crystallization kinetics of modified hydroxyapatite-enhanced poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) is a biodegradable material, and efforts have been devoted to enhancing its mechanical properties and biocompatibility for biomedical applications. However, there is a lack of research confirming the influence of nucleating agents on its crystallization behavior. In this study, the isothermal crystallization process was described using the Avrami model. The non-isothermal crystallization process was investigated using the Avrami-Jeziorny and Mo models. The effects of different calcium hydroxyapatite (CA-HA) contents on the nucleation activity, crystallization activation energy, and equilibrium melting point of P34HB/CA-HA composites were compared. The impact of CA-HA on the crystallization rate, nucleation rate, and crystal growth rate of the polymer matrix was discussed. The results indicate that with an increase in CA-HA content, the crystallization rate initially decreases and then increases. The minimum crystallization rate is observed at a CA-HA content of 9 wt%. Moreover, as the CA-HA content increases, nucleation activity is enhanced, suggesting that CA-HA acts as a nucleating agent, facilitating the nucleation process. When the CA-HA content exceeds 9 wt%, the increase in crystallization rate may be attributed to the further enlargement of molecular clusters formed by CA-HA, leading to a reduced dispersion of CA-HA in the polymer matrix. Furthermore, when the CA-HA content surpasses 9%, a significant decrease in crystallization activation energy is observed, indicating a reduction in the mobility of polymer chain segments.

Trace polymer coated clarithromycin spherulites: Formation mechanism, improvement in pharmaceutical properties and development of high-drug-loading direct compression tablets

Clarithromycin (CLA) is a high dose antibiotic drug exhibiting poor flowability and tabletability, making the tablet development challenging. This study aims to develop spherulitic CLA by introducing trace amount of polymer in crystallization solution. Its formation mechanism, physicochemical properties and potential for the direct compression (DC) tablets development were also investigated. Morphological analyses and the in situ observation on crystallization process revealed that the CLA spherulites are formed by fractal branching growth from both sides of the threadlike precursor fibers. 1H NMR analysis and nucleation time monitoring indicated that the existence of hydroxypropyl cellulose in solution slowed down the crystal nucleation and growth rate by forming hydrogen bonding interactions with CLA molecules, making the system maintain high supersaturation, providing high driving forces for CLA spherulitic growth. In comparison to commercial CLA, the CLA spherulites exhibit profoundly improved flowability, tabletability and dissolution behaviors. XPS, contact angle and Raman mapping analysis confirmed the presence of a thin HPC layer on the surfaces and interior of CLA spherulitic particles, resulting in increasing powder plasticity, interparticulate bonding strength and powder wettability, thus better tabletability and dissolution performances. The improved flowability and tabletability of CLA spherulites also enabled the successful development of DC tablet formulation with a high CLA loading (82.8 wt%) and similar dissolution profiles to reference listed drug. This study provides a novel solid form of CLA with superior manufacturability for further development.

Extracting ice crystal nucleation and growth rates from calorimetry curves

Extracting ice crystal nucleation and growth rates from calorimetry curves

Diffusion zone evolution around growing crystals in combeite glass

AbstractThe precipitation of nonstoichiometric crystals (of different composition from the parent glass) motivated us to study the stoichiometric Na2O·2CaO·3SiO2 ( N2CS3) glass‐forming system comprehensively. The concentration profiles of Na and Ca in the diffusion zone around Na4+2xCa4−x[Si6O18], , crystals in an N2C3S glass were characterized by energy‐dispersive spectroscopy and were then theoretically described. We show that the diffusion zone is formed because of the rejection of part of calcium by the growing crystal. The radial variation of the Ca concentrations and the crystal nucleation rate through the diffusion zone were analyzed simultaneously. We found that the nucleation rate in the diffusion zone near the crystal–glass interface drastically decreases due to the increase in the work of critical cluster formation resulting from the composition change. In contrast, the diffusion activation barrier remains practically constant. Moreover, the Ca diffusion coefficients, DCa, in Na2O·2CaO·3SiO2 and CaO·SiO2 glasses show the same Arrhenius dependence, demonstrating that (surprisingly) DCa does not depend on the glass composition in the CaO·SiO2–Na2O·SiO2 metasilicate joint. This work provides the quantitative spatial distribution of chemical components in a partially crystallized glass, shedding light on solid solution crystallization in a glass‐forming liquid and its consequences.

Comprehensive analysis of early-stage hydration and microstructure evolution in Sufflaminate cement: Insights from low-field NMR and isothermal calorimetry

This study presented a comprehensive investigation of the early hydration reaction and microstructure evolution of sulfoaluminate cement (SAC) using low-field nuclear magnetic resonance (LF-NMR) and isothermal calorimetry (IC). LF-NMR, combined with total relaxation signal and transverse relaxation time (T2), was employed to characterize the evolution of evaporation water (EW) and the degree of hydration (αlf) during the initial stage of SAC hydration. The hydration process was divided into four phases. The relative content of different EW types within the paste was investigated, and the pore structure and specific surface area evolution of SAC paste were studied based on the T2. The heat release of hydration of SAC was measured using IC, and the hydration kinetics was fitted with the JMAK model. The results demonstrated that the early hydration reaction of SAC was a multidimensional controlled process influenced by various factors. Also, the crystallization nucleation rate of hydration products was inversely related to w/c. Furthermore, a successful nonlinear fitting between the weighted average of T2 and the hydration degree (αt) obtained from IC was established, providing a standard reference curve for studying hydration degree and microstructure. Finally, the hydration products and microstructure were investigated using, SEM, and TG, and the evolution of the compressive strength of SAC was also analyzed. This work gave valuable insights into SAC's early hydration behavior and microstructural development, which can contribute to a better understanding of its performance and potential applications.

Particle Formation Mechanism of TiCl4 Hydrolysis to Prepare Nano TiO2

This study utilizes Aspen Plus chemical process simulation software (V11), applies uniform nucleation theory and growth kinetics equations, and explores the particle formation mechanism of TiCl4 hydrolysis to prepare nano TiO2. In the water/ethanol system, the effects of the reaction time, reaction temperature, water addition, pH value, and ethanol amount on the crystal nucleation rate and TiO2 particle distribution (PSD) were studied in detail by adding triethanolamine dropwise and using the Aspen Plus chemical process software simulation calculation method. The calculation results indicate that at room temperature, the formation of TiO2 crystal nuclei mainly occurs in the first 300 s and then enters the growth stage. The reaction was carried out under neutral conditions at room temperature for 4 h in 1 mL TiCl4, 6 mL C6H15NO3, 15 mL H2O, and 30 mL C2H5OH. The maximum number of particles reached 195 mesh per cubic micrometer, and the particle size after crystal nucleus growth was smaller, with a D50 of 6.15 nm. The distribution curve shows a normal distribution, which is basically consistent with the experimental results. When studying various factors, it was found that controlling the reaction time within 60 min and maintaining the reaction temperature at room temperature can reduce the particle size D50 to 2.44 nm. Continuing to adjust the amount of water added, it was found that at 1 mL, D50 decreased again to 0.19 nm. Adjusting the pH value found that maintaining the neutrality did not change the particle size. Continuing to adjust ethanol, it was found that adding an appropriate amount of ethanol promoted nucleation and growth. At 4 mL, the maximum number of particles reached 199 mesh per cubic micrometer, but D50 slightly increased to 0.24 nm.

Effects of Structural Relaxation of Glass-Forming Melts on the Overall Crystallization Kinetics in Cooling and Heating.

In the theoretical treatment of crystallization, it is commonly assumed that the relaxation processes of a liquid proceed quickly as compared to crystal nucleation and growth processes. Actually, it is supposed that a liquid is always located in the metastable state corresponding to the current values of pressure and temperature. However, near and below the glass transition temperature, Tg, this condition is commonly not fulfilled. In such cases, in the treatment of crystallization, deviations in the state of the liquid from the respective metastable equilibrium state have to be accounted for when determining the kinetic coefficients governing the crystallization kinetics, the thermodynamic driving force of crystallization, and the surface tension of the aggregates of the newly evolving crystal phase including the surface tension of critical clusters considerably affecting the crystal nucleation rate. These factors may greatly influence the course of the overall crystallization process. A theoretical analysis of the resulting effects is given in the present paper by numerical solutions of the J(ohnson)-M(ehl)-A(vrami)-K(olmogorov) equation employed as the tool to model the overall crystallization kinetics and by analytical estimates of the crystallization peak temperatures in terms of the dependence on cooling and heating rates. The results are shown to be in good agreement with the experimental data. Possible extensions of the theory are anticipated and will be explored in future analysis.

Process optimization and crystallization kinetics of ammonium sulfate from wet ammonia‐based desulfurization

AbstractThere are some problems in the production of ammonium sulfate, a byproduct of the ammonia desulfurization process, such as small crystal size and uneven distribution. The evaporative crystallization kinetics of ammonium sulfate and the factors affecting the crystallization of ammonium sulfate for improving the quality of ammonium sulfate were studied. The results showed that the largest mean diameter of ammonium sulfate was obtained at a stirring speed of 400 r/min, evaporation temperature of 60 °C, and pH of 5.0. The particle size of the ammonium sulfate increased when the crystal seed was introduced. The metastable region of ammonium sulfate was determined by laser method. The crystallization process of ammonium sulfate was studied using population balance equations and intermittent dynamic method, and the empirical equation of nucleation rate and growth rate of ammonium sulfate crystallization was obtained. This experiment can provide a solution for the problems existing in the production of ammonium sulfate in the process of ammonia desulfurization.

A New Model of Crystallization in Magmas: Impact of Pre‐Exponential Factor of Crystal Nucleation Rate on Cooling Rate Exponent and Log‐Linear Crystal Size Distribution

AbstractThe processes that control the crystallization of magmas, namely nucleation and growth, remain poorly constrained. Classical nucleation theory (CNT) has so far not provided a unified framework to explain crystal number density in laboratory experiments and the field. We use numerical experiments to study the influence of different cooling rates and CNT parameters on the crystal number density measured under constrained conditions in laboratory experiments. With varying the magnitude of pre‐exponential factor (J0) of nucleation rate, which represents the number of cluster as heterogeneous nucleation sites, we find that the cooling rate exponent (ξ) of the crystal number density varies from 3/2 to −1, depending on the magnitude of J0, cooling rate and surface tension. Using the regime maps of ξ as functions of J0 and surface tension, we can successfully interpret the diversity of cooling rate exponents reported by laboratory experiments in terms of J0 and surface tension. For extreme case of a negative cooling rate exponent ξ = −1, we propose a new crystallization model with constant rates of nucleation and crystallization, which reproduces a log‐linear crystal size distribution. In this condition, it is interesting that the crystal growth rate is inversely proportional to time, even if the diffusion‐limited growth is inversely proportional to the square root of time. For the case study of zoning profiles in microlites formed by decompression‐induced crystallization during the Shinmoedake 2011 subplinian eruptions, the comparison between theoretical predictions and natural volcanic products supports that our model is well applicable to magma ascent processes.

Analysis of conditions of crystallization suppression in Fe40Ni40P14B6 melt

The critical cooling rates required for suppression of Fe40Ni40P14B6 melt crystallization were estimated in the framework of the formalism of classical theory of crystallization assuming homogeneous nucleation rate, linear isotropic growth and Kolmogorov-Johnson-Mehl-Arami kinetics. Both the calculated “time-temperature-transformation” diagrams and the integral form of the Kolmogov’s equation for the case of continuous cooling were used for the estimations. The temperature dependences of the rates of crystal nucleation and growth were calculated with using of the values of the thermodynamic and kinetic parameters governing the crystal formation in amorphous phase as well as with the three-parameter temperature dependence of diffusivity proposed in the study. The critical cooling rates for different combinations of the equations describing nucleation and growth of crystals were estimated and the conditions for the correct prediction of the glass forming ability of Fe40Ni40P14B6 melt were established.

Study on the Supercooling Characteristics of Freezing Soil Based On Nucleation Theory

AbstractThe clarification of freezing in a soil‐water system is critical for assessing the formation of a freezing zone and liquid water flow. The supercooling phenomenon of soil pore solutions has been found during the freezing process, but the mechanism remains poorly understood. In this study, we propose a free energy function of soil‐water systems based on the Classical Nucleation Theory. The analytical solution of the critical nucleation problem of saline soil‐water system is obtained by combining the initial freezing temperature model and Pitzer activity coefficients model in electrolyte solutions. Then, the freezing‐thawing experiments of saline soil with various salt contents were conducted for verifying the analytical solution. The derived boundary nucleation rate is the quantitative solution of the critical condition for the supercooling. The findings suggested that the theory results agreed well with the experiment results. For the salt‐free soil‐water system, the critical maximum radius of supercooling was 7.15 nm. We compared eight classical ice‐water interfacial tension models, and the “Reinhardt & Doye” and “DeMott & Rogers” models showed excellent performance when using the new free energy theoretical framework to predict the crystallization nucleation rate of soil‐water systems. A positive correlation between the boundary nucleation rate and soil‐water potential is detected. According to the influencing factors, the boundary nucleation rate of soil‐water system can be divided into three zones: salt nature control zone (R > 100 μm), salt‐pore mixed control zone (100 μm > R > 100 nm), and pore size control zone (R < 100 nm).

Nanocrystallization of Cu46Zr33.5Hf13.5Al7 Metallic Glass

The recently discovered Cu46Zr33.5Hf13.5Al7 (at.%) bulk metallic glass (BMG) presents the highest glass-forming ability (GFA) among all known copper-based alloys, with a record-breaking critical casting thickness (or diameter) of 28.5 mm. At present, much remains to be explored about this new BMG that holds exceptional promise for engineering applications. Here, we report our study on the crystallization behavior of this new BMG, using isochronal and isothermal differential scanning calorimetry (DSC), X-ray diffraction (XRD), and transmission electron microscopy (TEM). With the calorimetric data, we determine the apparent activation energy of crystallization, the Avrami exponent, and the lower branch of the isothermal time–temperature–transformation (TTT) diagram. With XRD and TEM, we identify primary and secondary crystal phases utilizing samples crystallized to different degrees within the calorimeter. We also estimate the number density, nucleation rate, and growth rate of the primary crystals through TEM image analysis. Our results reveal that the crystallization in this BMG has a high activation energy of ≈360 kJ/mole and that the primary crystallization of this BMG produces a high number density (≈1021 m−3 at 475 °C) of slowly growing (growth rate < 0.5 nm/s at 475 °C) Cu10(Zr,Hf)7 nanocrystals dispersed in the glassy matrix, while the second crystallization event further produces a new phase, Cu(Zr,Hf)2. The results help us to understand the GFA and thermal stability of this new BMG and provide important guidance for its future engineering applications, including its usage as a precursor to glass–crystal composite or bulk nanocrystalline structures.