Crystallization Mechanism Research Articles

Study on the supercooling and crystallization mechanism of saline soil based on thermodynamic framework

Quantifying the supercooling characteristics of saline soil–water systems is essential for engineering and agriculture in cold regions. However, the crystallization mechanism of supercooling remains unclear. We conducted experimental observations to investigate the impact of salinity on the soil supercooling properties. Additionally, a freezing nucleation thermodynamic model for saline soil was established based on the Negentropic Nucleation Framework (NNF). Statistical analysis methods were employed to analyze the sensitivity of the parameters and interpret the supercooling microscopic mechanism. The results indicated that the supercooling degree distribution of saline soil is best described by a normal distribution (hypothesis testing statistic Dn=0.176). The nucleation rate was primarily controlled by water activity and activation energy of water molecules. The concentration of salt solution played a crucial role in promoting the formation and growth of crystal nuclei. However, the promoting effect decreased with increasing solution concentration when the concentration was below 0.3 mol/L. Moreover, the nucleation potential energy barrier increased with salt concentration, with NaCl environment exhibiting a higher nucleation potential energy barrier compared to Na2SO4 environment at the same salt concentration. In summary, this research provides a theoretical reference for revealing the freezing-thawing hysteretic mechanism and improving the accuracy of numerical calculation models in cold regions.

A simplified method for the recycling of spent lithium-ion batteries via manganese selective recovery by anoxic ammonia leaching and spontaneous precipitation

Due to the high cost of the manganese solvent extraction process in the conventional recycling of spent NCM-ternary lithium-ion batteries (LIBs), we employed an anoxic complexation ammonia leaching-spontaneous precipitation process to selectively recover manganese from the black mass of spent ternary LIBs. This innovation serves as a substitution for the conventional acid leaching-manganese solvent extraction, aiming to reduce costs and enhance the efficiency of the recycling process. Specifically, the controlled reduction roasting was performed to achieve the dissociation of LiNixCoyMnzO2 and the phase transition to MnO and metallic Ni and Co. Exploiting this difference, ammonia-ammonium carbonate were employed as leaching agents, which enabled the selective leaching of over 96 % of manganese, while those of nickel and cobalt were only 1.2 % and 2.6 %. After filtration, the MnCO3 product with high purity was precipitated by allowing the leachate to stand for 12 h without adding any reagent. The ammonia solution could be circulated to leaching the subsequent batch of spent LIBs. Thermodynamic calculations were used to elucidate the leaching and crystallization mechanisms. Comparative process analysis and economic assessments confirmed that the proposed new method is extremely appealing due to its high selectivity, considerable economic advantages, and environmental benefits.

Crystal plasticity finite element modelling and mechanical deformation mechanism of nanolaminated graphene reinforced metal matrix composites

Metal matrix composites with certain hierarchical structures are potential to break out the conflicts between strength and toughness. Nano-carbon like graphene (Gn) reinforced metal matrix composites with nanolaminated structures have been largely developed to overcome this issue. However, the plastic deformation mechanism hiding behind the nanolaminated structures is still lacking. In this study, crystal plasticity finite element simulations and composite structure modeling are combined in order to uncover the mechanical deformation behavior of nanolaminated Gn/Al composites. Different lateral Gn sizes of 180, 360 and 720 nm are considered, while the hybrid lateral Gn sizes of 180 and 720 nm are applied as well. Good consistency between experimental and numerical results indicates the reliability of performed simulations. It is found that the strengthening and hardening behaviors of Gn/Al composites are dominated by Gn rather than Al matrix. The edges of Gn serving as a major dislocation nucleation source produce localization of plastic deformation, while the interiors of Gn activate more slip systems but reduce total shear strains. The edges and interiors of Gn determine the stability of plastic deformation of Gn/Al composites; large edge vs. interior area of Gn will lead to early necking. The rule of mixture fails in predicting the peak tensile strength and tensile strain of Gn/Al composites with hybrid lateral Gn sizes, because the microscopic plastic deformation can largely localize around 180 nm Gn in these hybrid Gn/Al composites. This work is enlightening to design and develop novel smart metal matrix composites.

High temperature Raman spectroscopic analysis of the crystal growth of Bi2ZnOB2O6

Micromechanism of crystal growth has received considerable attention as a fundamental subject. However, in situ observation of the crystal growth process remains challenging. In this study, high-temperature Raman spectroscopy has been utilized to investigate the growth pattern of Bi2ZnOB2O6 crystals via in situ exploration of the starting solution structure near the crystal–solution interface. The experimental results show that the solution primarily consists of ZO4 and BO3 units corresponding to 370, 539, 664, and 1293 cm−1 vibration frequencies. These units connect with each other forming longer chains in the area close to the crystal, and they are related to the presence of low-wavenumber vibrations in the Raman spectrum. Furthermore, a loose embryonic structure of the Bi2ZnOB2O6 crystal is observed near the crystal–solution interface owing to the formation of Bi–O bonds. Therefore, this study successfully provides a clear understanding of the formation mechanism of Bi2ZnOB2O6 crystals.

Surface outflow effect on dislocation structures in micrometer-sized metals

Dislocations in metals often multiply and agglomerate into quasi-ordered structures with various morphologies in cyclic loading experiments. Specifically in face-centered cubic metals, the shapes of dislocation clusters change from dislocation bundle structures (called veins) to ladder-like periodic wall structures at a threshold of the applied shear strain that coincides with the fracture initiation threshold. In these ladder-like structures, the interval between adjacent walls is 1 or 2μm, regardless of the material dimensions. The robustness of such micrometer-sized wall intervals implies the impossibility of forming ladder-like structures in micrometer-sized metals. Nonetheless, the kind of dislocation structure that will occur is unclear because of a lack of knowledge about small-scale metal fatigue. In this study, we theoretically speculate the dislocation structures formed in micrometer-sized metals using differential equations that describe the reaction and diffusion of dislocations in the fatigue process. We find that micrometer-sized metals form few-walled structures due to the outflow of dislocations from their free surfaces, even under the parameter conditions under which vein structures form in macroscopic metals. The results indicate that the fracture initiation limit can be decreased by reducing the system size, which contradicts the well-established “smaller is stronger” consensus regarding the mechanics of small-volume single crystals.

Challenges and strategies towards the interface between lithium anode and Li10GeP2S12 electrolyte in all-solid-state lithium metal batteries

All-solid-state lithium (Li) metal batteries (ASLMBs) have attracted enormous attention due to the safety of solid-state electrolytes (SSEs) and the high energy density of Li metal. Among various SSEs, sulfide SSEs, especially the Li10GeP2S12 (LGPS), shows liquid electrolytes comparable conductivity at room temperature, thus being considered as one of the most promising candidates. However, the interfacial issues with Li have severely hindered the further development of the LGPS-based ASLMBs. Herein, we present the distinctive crystal structure and ion transport mechanism of LGPS at first. The origin of the interfacial issues with Li and the corresponding modification strategies are summarized then. Finally, combined with the present opportunities and challenges, perspectives are presented in the end for designing practically accessible LGPS-based ASLMBs in the future.

Fluoride- and Seed-Free Synthesis of Pure-Silica Zeolite Adsorbent and Matrix Using OSDA-Mismatch Approach.

The pure-silica zeolite plays a crucially important role in the gas separation of alkane/alkene, the low-k dielectric material, and the robust matrix for confining metal species during catalysis. However, the environmentally friendly synthesis of pure-silica zeolites is still challenging since (1) the toxic fluoride or dealuminum seeds are inevitably utilized through the hydrothermal synthesis and (2) it will also take a longer crystallization time. Herein, we present an efficient method called the OSDA-mismatch approach for the fluoride- and seed-free synthesis of pure-silica zeolites using Si-SOD (enriched 4-rings) as the sole silica source. This approach allows for the rapid and green synthesis of 15 pure-silica zeolites (CHA, *BEA, EUO, SFF, STF, -SVR, *-SVY, DOH, MTN, NON, *MRE, MEL, MFI, MTW, and *STO). Furthermore, distinct crystallization mechanisms of two significant pure-silica CHA- and *BEA-type zeolites (denoted as Si-CHA and Si-BEA) are investigated in detail by advanced characterization techniques such as FIB, 3D ED, 4D-STEM, HRTEM, Raman, and 29Si MAS NMR. More importantly, Si-CHA displays promising propane/propylene separation performance even better than the one synthesized in the presence of toxic HF. In addition, the incorporation of Zn species within Si-BEA fabricated by this approach also renders superior performance on propane dehydrogenation.

RETRACTED: Exploiting Cu+–Na+ ion‐exchanged and Ar/H2 annealed glass matrix to synthesize copper nanoparticles

AbstractCopper nanoparticles (CuNPs) were successfully prepared in Cu+–Na+ ion‐exchanged commercially available silicate glasses followed by being annealed in Ar/H2 atmosphere; in an approach that can be quite economic capable of modifying the physicochemical properties of glass. This approach resulted in the growth of spherical and crystalline CuNPs, with an average size of 67.5 nm, which is greater than the CuNPs average size obtained with annealing at air atmosphere (15.8 nm). On the treated glasses, phase transitions indicative of a shape memory effect and dendritic structures were also detected, indicating their vital roles, as crystal growth mechanisms in the resultant CuNPs. The surface plasmon peaks of CuNPs have been clearly observed in absorption spectra of doped annealed glasses at 350, 450, and 550°C in Ar/H2. Photoluminescence studies have proved the presence of both Cu+ and Cu2O. The detailed methodology and the structural and morphological characterizations of the annealed copper ion‐exchanged samples were carried out using optical microscopy (OM), X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy and high‐resolution TEM (TEM and HRTEM), and their reasoning are thoroughly described and discussed.

Investigation on the Microstructural Diversity of a Three-Dimensional Porous Hydroxyapatite/Wollastonite Skeleton via Biomineralization in Simulated Body Fluids

The occurrence of fractures has emerged as one of the most prevalent injuries in the human body. In bone reconstruction surgery, after the implantation of porous hydroxyapatite materials, there is an initial infiltration of body fluids into the porous implant, followed by biomineralization-mediated apatite crystal formation and the subsequent ingrowth of bone cells. Despite extensive research efforts in this field, previous investigations have primarily focused on the formation of apatite crystals on exposed surfaces, with limited literature available regarding the formation of apatite crystals within the internal microstructures of bone implants. Herein, we demonstrate the occurrence of dynamic biomineralization within a three-dimensional porous hydroxyapatite/wollastonite (HA/WS) skeleton, leading to the abundant formation of nano-sized apatite crystals across diverse internal environments. Our findings reveal that these apatite nanocrystals demonstrate distinct rates of nucleation, packing densities, and crystal forms in comparison to those formed on the surface. Therefore, the objective of this study was to elucidate the temporal evolution of biomineralization processes by investigating the microstructures of nanocrystals on the internal surfaces of HA/WS three-dimensional porous materials at distinct stages of biomineralization and subsequently explore the biological activity exhibited by HA/WS when combined with cell investigation into apatite crystal biomineralization mechanisms at the nanoscale, aiming to comprehend natural bone formation processes and develop efficacious biomimetic implants for tissue engineering applications. The simultaneous examination of bone cell attachment and its interaction with ongoing internal nanocrystal formation will provide valuable insights for designing optimal scaffolds conducive to bone cell growth, which is imperative in tissue engineering endeavors.

Preparation and growth mechanism of YFeO3 magneto optic crystals

YFeO3 is one of important magneto optic crystals with perovskite structure. The anisotropy of the crystal leads to different physical and chemical properties of the crystal in different directions. In this work, YFeO3 crystals were grown by hydrothermal method and the effects of different mineralizers on the crystal growth were investigated. The results showed that the mineralizer could affect the growth direction of crystal plane during the hydrothermal crystallization process. YFeO3 crystals with various morphologies were grown by adjusting the concentration of the mineralizer under hydrothermal conditions. The transformations between the crystal planes during crystallization were studied by modeling, and the stabilities of {002} and {110} crystal planes under the action of KOH and NaOH were determined. The effects of urea on YFeO3 crystal planes and NH4+ on {002}, {020} and small crystal planes were investigated. Furthermore, the exposure ratio of YFeO3 crystal plane has great influence on its magnetization and coercive field. Finally, the formation and change mechanism of YFeO3 crystals by the hydrothermal method were proposed, providing evidence for further study of the dependence of the shape of YFeO3 on ferromagnetism.

In situ study on nucleation mechanism and surface morphology of zinc thiourea sulfate crystals

Different nucleation phenomena and defect formation were observed in scanning experiments on the (100) faces of zinc thiourea sulfate (ZTS) crystals using Atomic Force Microscopy (AFM). It was found that nucleation is easily induced near microcrystals, but two-dimensional nuclei do not appear continuously. Edge dislocation can be preferred for nucleation, but the time of occurrence of two-dimensional nuclei near the surface of the edge dislocation is not the same as the growth rate. When two-dimensional nuclei and dislocations co-exist, the step heights have a significant impact on which growth mechanism ultimately dominates. In addition, the experimental results show that the defects produced on the surface of ZTS crystals mainly include hollow defects, pits and liquid inclusions. The causes of the different defects are discussed. It is found that the height of the step has an important influence on the formation of liquid inclusions and their possible influence on the surface morphology is analysed.

Micromorphology of hesperidin crystals and ultrastructure of crystal-bearing cells in Metrodorea nigra, a neotropical Rutaceae species

Researches on the developmental and morphological features of organic crystals in plants are relatively scarce. Hesperidin is a flavanone glycoside found abundantly in Rutaceae, mainly in Citrus fruits. Due to the variety of biological activities, hesperidin is one of the most promising bioflavonoids. We investigated the distribution, micromorphology and intracellular localization of hesperidin crystals in the vegetative organs of Metrodorea nigra, a neotropical Rutaceae tree. Additionally, we analyzed the ultrastructural organization of crystal-bearing cells. Bright field, epifluorescence and polarized-light microscopy, scanning (SEM) and transmission electron microscopy (TEM) analysis were performed. Hesperidin crystals appeared as needle-shaped crystals forming plumose clusters under SEM, and as acicular solitary crystal or aggregate yellow/brown twisted filaments inside cells under light microscope. Hesperidin and calcium oxalate crystals often occurred together in the epidermis and mesophyll tissues. Hesperidin crystals were abundant inside the phloem, while calcium oxalate crystals were absent in the vascular tissues. Phenolic substances occurred in all tissues, but they were abundant within vascular tissues. Flavonoid autofluorescence in blue color was associated with crystals in the cell walls and cytoplasm. The crystal-bearing cells exhibited extensive rough endoplasmic reticulum (RER) and associated vesicles filled with electron-dense materials, proliferation of the tonoplast and abundance of multilamellar bodies containing electron-dense or crystalline materials close to irregular plasmalemma. Our ultrastructural observations allow us to speculate that the RER and tonoplast membranes and associated vesicles appeared to be involved in the packaging and channeling of the materials toward the cell walls. Crystals of hesperidin and calcium oxalate occurred on the surface of common epidermal cells and glandular trichomes. The mechanisms of condensation, crystallization and extrusion of hesperidin crystal through the cell walls remain to be investigate, and could be an interesting subject for future studies.

Damage on asphalt surfaces caused by ionic solution erosion and salt crystallization at molecular scale

The damage mechanism of severe salt corrosion on asphalt surfaces should be revealed at molecular scale. This study utilized molecular dynamics (MD) and density functional theory (DFT) simulations to investigate damage degree and mechanism of ionic solution erosion and salt crystallization on asphalt surfaces. Various asphalt-solution and asphalt-salt interfaces models were built, while interfacial interaction, diffusion, adhesion, and electronical properties were calculated. The electrostatic interaction played a critical role both in solution-asphalt and crystal-asphalt systems, particularly between anions and asphalt. All ions adsorbed onto unaged asphalt surfaces and eroded into unaged asphalt interiors while only cations penetrated into aged asphalt due to electronical repulsions between anions and SO/CO, indicating cation erosion contributed more to salt damage during aging. Salt crystals participated and expanded on asphalt surfaces, resulting in micro-cracks and micro-voids. Sulfates adhered asphalt more than chlorides because sulfates had closer interval distance and larger free volumes with asphalt. Asphalt molecules with high polarity and more charge were more susceptible to interact by ions. The salt damage on asphalt mainly included solution perpetration and crystal adhesion. The order of salt damage of cations to asphalt is: Mg2+ > Na+ > Ca2+, and of anions is: SO42− > Cl−.

Comprehensive Understanding of Structure Transition in LiMnyFe1−yPO4 during Delithiation/Lithiation

AbstractThe complexity of structural changes in LiMnyFe1−yPO4 (LMFP) during delithiation/lithiation poses unique challenges in kinetics and cycling, distinguishing it significantly from LiFePO4. Therefore, comprehending the delithiation/lithiation mechanism of LMFP is essential to optimize material design, synthesis, and battery application management. However, existing reports show apparent discrepancies and contradictions. This paper elucidates the relaxation property of LMFP, providing a comprehensive review of crystal structure and electronic structure change mechanisms during delithiation/lithiation based on in situ characterization. Regarding crystal structure transition, variations in LMFP's compositional uniformity across different literature, stemming from differences in the synthesis process, may contribute to multiple mechanisms. Concerning electronic structure changes, the chemical environments between Fe and Mn are mutual interaction, and the sluggish kinetics of the Mn2+/Mn3+ reaction suggest partial charge compensation by oxygen in the phosphate group. Building on these findings, the paper addresses existing research deficiencies and identifies potential directions for future investigations into the delithiation/lithiation mechanism of LMFP, aiming to provide a solid theoretical foundation for developing new olivine‐type cathode materials with superior electrochemical performance.

Perspective from a Hubbard U-density corrected scheme towards a spin crossover-mediated change in gas affinity.

By employing a recently proposed Hubbard U density-corrected scheme within density functional theory, we provide design principles towards the design of materials exhibiting a spin crossover-assisted gas release. Small molecular fragments are used as case study to identify two main mechanisms behind the change in binding energy upon spin transitions. The feasibility of the proposed mechanism in porous crystals is assessed by correlating the change in binding energy of CO2, CO, N2, and H2, upon spin crossover, with the adiabatic energy difference associated with the spin state change of the square-planar metal in Hofmann-type clathrates (M = Fe, Mn, Ni). A few promising cases are identified for the adsorption of intermediate ligand field strength molecules such as N2 and H2. The latter stands out as the most original result as the strong interaction in low spin, as expected from a Kubas mechanism, results in a large change in binding energy. This work provides a general perspective towards the engineering of open-metal site frameworks exhibiting local environments designed to have a spin crossover upon adsorption of specific gas molecules.

Superplastic deformation inside the knife-sharp shear bands in mid-crustal granites

We examined the microstructures of three ductile shear bands of granitic composition that deformed under mid-to-upper greenschist facies. These shear bands, from the Bundelkhand Craton, India, are 0.8–4.4 mm thick with 20–30 μm median grain sizes and share sharp contacts with the host granite. Comminution of the rheologically stronger feldspars increased permeability, promoted fluid influx, and allowed strain localisation in the incipient shear bands. The major components, quartz and feldspars, deformed via phase-specific crystal plastic deformation mechanisms. Quartz in the monomineralic bands deformed predominantly via dislocation creep, while the feldspars deformed via diffusion creep. Finer quartz grains, which occur at plagioclase triple junctions, resulted from myrmekitisation – also evident from the anti-clustered distribution of quartz-plagioclase phase boundaries and CPO inheritance. The weak CPOs and high mean misorientation angles of the fine plagioclase and K-feldspar grains and yet a high shear strain (γ = 16–37) suggest a significant contribution of grain boundary sliding (GBS) in strain localisation inside the ductile shear bands. Since intracrystalline slip alone cannot explain the high ductile strain in the shear bands, we suggest that GBS controlled the deformation and maturation of the shear bands and promoted superplasticity to accommodate further shearing.

Crystallization behavior and properties of quartz glass-ceramics synthesized from desert sand

Quartz glass-ceramics were synthesized with desert sand as the main raw material. The effects of pretreatment technology of desert sand and various cations on the glass stability (GS) parameters (KH, KLL,KW, KZW, KLX), crystallization kinetic parameters (crystallization activation energy (Ec), reaction rate (k), the effective frequency factor(ν) and the Avrami parameter (n)), phase transition, microstructure and properties of glass-ceramics were investigated. The results show that the chemical composition of desert sand is greatly changed by sieving and magnetic separation, and the glass stability, phase transition and crystallization ability of glass are controlled by the mixed mobile ion effect (MMIE), in which the ionic field intensity determined by ionic valence and radius plays a major role. Finally, the crystallization of glass is dominated by the surface crystallization mechanism, and the obtained glass-ceramics mainly consist of α-quartz, β-cristobalite and glass phases, which have excellent comprehensive properties.

Preparation and formation mechanism of colorful photonic crystals on rough yarns

The environmentally friendly dyeing of textiles combining regular photonic crystals (PCs) has shown remarkable promise for application. However, the surface is rough and undulating and contains many harnesses due to full-curved structure of yarns. All these factors increase the difficulty of assembling colloidal microspheres into regular PCs on yarns. Therefore, relevant studies on the preparation methods and fundamental theories for constructing bionic structural colors on conventional flexible yarns are few. This study contains two main parts: first, regular PC-based yarns were produced by the dip coating method with poly (styrene–butyl acrylate–methacrylate) (P(St–BA–MAA)) as building block. Specifically, the softness and surface flatness of acrylic yarns were improved using silicone-modified polymer solution and cationic acrylate solution. The results indicated that assembling of PC with vivid structural color was easier when the base color of yarns was black and the concentration of P(St–BA–MAA) colloidal microspheres was about 60 wt%. Second, the self-assembling mechanism of microspheres on acrylic yarns was further studied by untwisting and slicing. The results showed that colloidal microspheres would fill the surfaces and voids of the outer fibers of acrylic yarns to form regular PCs, and they would also enter the inner fibers of yarns by capillary forces. However, the structure of yarns was tight inside and loose outside due to twisting and other reasons. Therefore, the colloidal microspheres had more difficulty entering the fibers on the inner side of the yarn to form an ordered PC structure when the fibers were closer to the yarn axis. The PC-based colored yarn also remained bright after the rubbing test. The color phase of the structured colored yarns based on PC could be adjusted as well by regulating the particle size and the observation angle. The prepared structured colored yarns were woven into fabrics, which were named yarn-structure colored fabrics. This research provides theoretical support and technical guidance for the preparation and practical application of flexible structured colored yarns based on PC.

Current Challenges and Advanced Design Strategy of Vanadium Dioxide Cathode for Low‐Cost Aqueous Zinc Metal Battery

Rechargeable aqueous zinc metal battery has been one of the next‐generation energy storage systems with a promising future due to the advantages of aqueous electrolyte and metallic zinc anode. Among many cathode materials, vanadium‐based materials with considerable specific capacity, adjustable crystal structure, and multiple valence states are very promising cathodes, but the electrochemical performance of vanadium‐based zinc metal batteries faces severe challenges such as the limited and declining capacity and sluggish ion/e− transport kinetics process. Herein, taking VO2 as an example, the crystal structure and energy storage mechanism of VO2 cathode are briefly introduced. The challenges of aqueous Zn/VO2 battery are analyzed in depth. Significantly, the current advanced modification strategies for aqueous Zn/VO2 battery are summarized and discussed in detail, and the future development is also prospected. This article can provide some significant references for the development of aqueous Zn/VO2 battery and the guiding significance for other metal ion battery.

Kinetic partitioning of trace cations between zoned clinopyroxene and a variably cooled-decompressed alkali basalt: Thermodynamic considerations on lattice strain and electrostatic energies of substitution

We present kinetic partitioning data for trace cations measured in zoned clinopyroxene crystals obtained from a variably cooled and decompressed olivine basalt erupted at Mt. Etna volcano in Italy. Supersaturation effects and compositional heterogeneities at the interface melt lead to the development of sector zoning, concentric zoning, and patchy zoning in clinopyroxene crystals. Apparent partition coefficients between compositionally different growth layers and adjacent melts (Di) for isovalent groups of trace elements are tested for internal consistency on the thermodynamic basis of lattice strain (ΔGstrain) and electrostatic (ΔGelec) energies of substitutions. The excess energy of partitioning (ΔGpartitioning) for trace cations in zoned crystals accounts for a kinetic incorporation control leading to large enthalpic effects through distortion of the lattice and changes in the electrostatic forces. ΔGpartitioning depends upon the complementary relationship between ΔGstrain and ΔGelec, which is the most appropriate thermodynamic description for the accommodation of rare earth elements and high field strength elements in the lattice site of zoned crystals. Polyhedral sectors, skeletal forms, and overgrowth zones have Di values settled by the number of charge-balanced and -imbalanced configurations taking place in the lattice site as a function of aluminium in tetrahedral coordination, and crystal structural changes produced by heterovalent cation substitutions. In an energetically unstable macroscopic system ruled by cooling and decompression, thermodynamic requirements for the crystallochemical control of Di encompass the attainment of local equilibrium at the crystal-melt interface via the establishment of small-volume reaction kinetics. The requisite of local interface equilibrium is however susceptible to the anisotropic growth velocity of each specific clinopyroxene surface, thereby giving reason to different energetic properties of the crystallographic site. This axiomatic control requires that transition metal cations partition also in consideration of electronic effects related to the crystal field stabilization energy. The overriding implication is that Di values for trace cations having different size, charge, and electronic configuration serve as sensitive probes of the different crystal growth mechanisms, surface incorporation sites, and arrangements of atoms at the lattice-scale. In this perspective, fractional crystallization modeling of 2011–2013 bulk rock data from lava fountains indicates that the compositional evolution of magmas erupted at Mt. Etna cannot be described by a unique equilibrium value of Di for a given clinopyroxene-melt interface. The leverage of interface kinetics is distinctively dominant along the subvolcanic plumbing system, thereby requiring that values of Di differ for structurally and compositionally distinct zones in clinopyroxene phenocrysts. To successfully interpret the trace element signature of Etnean magmas, the archetypal constancy of partition coefficient at bulk thermodynamic equilibrium must be in some measure reappraised in favor of the establishment of a local interface equilibrium upon highly dynamic crystallization and growth conditions.