Nanoscale Heterogeneity Research Articles

Control and Impact of Metal Loading Heterogeneities at the Nanoscale on the Performance of Pt/Zeolite Y Catalysts for Alkane Hydroconversion.

The preparation of zeolite-based bifunctional catalysts with low noble metal loadings while maintaining optimal performance has been studied. We have deposited 0.03 to 1.0 wt % Pt on zeolite H-USY (Si/Al ∼ 30 at./at.) using either platinum(II) tetraammine nitrate (PTA, Pt(NH3)4(NO3)2) or hexachloroplatinic(IV) acid (CPA, H2PtCl6·6H2O) and studied the nanoscale Pt loading heterogeneities and global hydroconversion performance of the resulting Pt/Y catalysts. Pt/Y samples prepared with PTA and a global Pt loading as low as 0.3 wt % Pt (nPt/nA = 0.08 mol/mol, where nPt is the number of Pt surface sites and nA is the number of acid sites) maintained catalytic performance during n-heptane (T = 210–350 °C, P = 10 bar) as well as n-hexadecane (T = 170–280 °C, P = 5 bar) hydroisomerization similar to a 1.0 wt % Pt sample. For Pt/Y catalysts prepared with CPA, a loading of 0.3 wt % Pt (nPt/nA = 0.08 mol/mol) sufficed for n-heptane hydroisomerization, whereas a detrimental effect on n-hexadecane hydroisomerization was observed, in particular undesired secondary cracking occurred to a significant extent. The differences between PTA and CPA are explained by differences in Pt loading per zeolite Y crystal (size ∼ 500 nm), shown from extensive transmission electron microscopy energy-dispersive X-ray spectroscopy experiments, whereby crystal-based nPt/nA ratios could be determined. From earlier studies, it is known that the Al content per crystal of USY varied tremendously and that PTA preferentially is deposited on crystals with higher Al content due to ion-exchange with zeolite protons. Here, we show that this preferential deposition of PTA on Al-rich crystals led to a more constant value of nPt/nA ratio from one zeolite crystal to another, which was beneficial for catalytic performance. Use of CPA led to a large variation of Pt loading independent of Al content, giving rise to larger variations of nPt/nA ratio from crystal to crystal that negatively affected the catalytic performance. This study thus shows the impact of local metal loading variations at the zeolite crystal scale (nanoscale) caused by different interactions of metal precursors with the zeolite, which are essential to design and synthesize optimal catalysts, in particular at low noble metal loadings.

The role of nano-scale elastic heterogeneity in mechanical and tribological behaviors of a Cu–Zr based metallic glass thin film

Despite its significance in fundamentally understanding mechanical behaviors of metallic glasses, the effect of elastic heterogeneity on plastic deformation and thereby nanotribological behavior of metallic glass thin films (MGTFs) remains an open question. By a combination of nano-scratch, nano-DMA and nanoindentation tests, we have investigated in the present work the room-temperature inhomogeneous plastic deformation behavior and nanotribological properties of Cu–Zr based MGTFs obtained by magnetron sputtering with different substrate temperatures. It is revealed that while the studied MGTF experiences a moderate rise of both hardness and Young's modulus with the elevating substrate temperature from 300 K to 473 K, its wear resistance significantly increases during the nano-scratch under a ramping load. More interestingly, through systematically studying the serration dynamics during the nano-scratch for MGTFs with different thermal history, we found that the increase of critical length scale for shear banding, which is well accompanied by the reduction of nano-scale elastic heterogeneity, tends to make shear banding more difficult in the amorphous structure, and thus enhance the wear resistance of the tested MGTFs. The current findings may provide a useful guidance to develop MGTFs with a superior mechanical and tribological properties via tuning their nanoscale elastic heterogeneity.

Incorporation of incompatible trace elements into molybdenite: Layered PbS precipitates within molybdenite

Abstract Trace elements in molybdenite can provide important information regarding the composition of ore-forming fluid and the evolution and genesis of ore deposits. However, the occurrence states and behavior of relatively incompatible trace elements (e.g., Pb and Os) in natural molybdenite remain ambiguous. Here, we report an abnormally high enrichment of Pb and layered PbS precipitate within molybdenite grains from the Huanglongpu carbonatite-hosted Mo-Pb deposit in the Qinling orogenic belt of Northern China. High-resolution transmission electron microscopy (HRTEM) and related nanobeam techniques were applied to characterize the occurrence states of Pb within molybdenite at the atomic scale. The results show that up to several weight percent of Pb can be incorporated into the molybdenite structure during initial crystallization, which can lead to the formation of screw dislocations and 3R/disordered stacking of S-Mo-S sandwich layers. Observations using a scanning transmission electron microscope also reveal that Pb diffuses from the host molybdenite into the layered PbS precipitates under prolonged electron beam irradiation. Pb-bearing molybdenite tends to transform into a Pb-poor ordered 2H1 polytype upon Pb exsolution during cooling. Pb preferentially exsolves along the (001) plane of molybdenite and is stored in structural defects (e.g., dislocation loops) and grain boundaries, resulting in nano-scale Pb heterogeneities in molybdenite. Further coarsening of the exsolved Pb results in the formation of layered PbS precipitates along the (001) plane of molybdenite. This study provides an example of the consequences of the incorporation and exsolution of incompatible trace elements in molybdenite and demonstrates that careful mineralogical examination is required to interpret geochemical data obtained by in situ analysis techniques.

Modelling flexural wave propagation by the nonlocal strain gradient elasticity with fractional derivatives

The flexural wave propagation in a microbeam is studied based upon the nonlocal strain gradient model with the spatial and time fractional order differentials in the present work. To capture the dispersive behaviour induced by the inherent nanoscale heterogeneity, the stress gradient elasticity and the strain gradient elasticity are often used to model the mechanical behaviour. The present model incorporates the two models and introduces the fractional order derivatives which can be understood as a generalization of integral order nonlocal strain gradient model. The Laplacian operator in the constitutive equation is replaced with the symmetric Caputo fractional differential in the present model. To illustrate the flexibility of the present model, the flexural wave propagation in a microbeam is studied. The fractional order in the present model as a new material parameter can be adjusted appropriately to describe the dispersive properties of the flexural waves. The numerical results based on the new nonlocal strain gradient elasticity with fractional order derivatives are provided for both Euler–Bernoulli beam and Timoshenko beam. The comparisons with the integer order nonlocal strain gradient model and the molecular dynamic simulation are performed to validate the flexibility of the fractional order nonlocal strain gradient model.

Temperature dependent fracture behavior in model epoxy networks with nanoscale heterogeneity

The role of nanoscale heterogeneity on the mode I fracture toughness, KIc, of model epoxy networks has been investigated. Model systems utilized consist of diglycidyl ether of bisphenol A (DGEBA) as the epoxide with a stoichiometric amine mixture of a rigid cycloaliphatic diamine (PACM) and a more flexible, polypropylene glycol based diamine (Jeffamine) at different molar ratios. The molecular weight of the Jeffamine was adjusted to further tailor the epoxy properties. Fracture toughness was measured using single edge notched bend samples and hardness was measured by Vickers indentation. Both measurements were performed at temperatures as low as −100 ̊C to above ambient temperatures. Results are interpreted in the context of the Dugdale model of material toughness where the fracture toughness is expressed in terms of a cohesive zone stress (related to the hardness), the elastic modulus (measured directly) and the crack tip opening displacement (obtained from images of the fracture surfaces). High toughness is obtained in heterogeneous networks where a decrease in the cohesive zone stress is offset by sufficiently large increases in the crack tip opening displacement.

Identification of rejuvenation and relaxation regions in a Zr-based metallic glass induced by laser shock peening

In this paper, laser shock peening (LSP) treatment was performed on Zr35Ti30Cu10Ni5Be20 bulk metallic glass (BMG) and the effects of induced energy on the characteristics of glassy structure were evaluated. The high resolution atomic force microscopy (AFM) and nanoindentation tests were carried out to characterize the nanoscale heterogeneity and micromechanical properties in the depth of material. According to the results, the surface of material showed a high heterogeneous structure, which was the sign of structural rejuvenation. However, with the move into the depth of material, the nanoscale heterogeneity decreased and eventually a relaxed region with the minimum heterogeneity was found in the 1.5–2 mm depth of BMG sample. Passing the relaxed region, again the nanoscale heterogeneity similar to the as-cast sample was observed. The nanoindentation results also confirmed the AFM outcomes. It is suggested that the relaxed region at the neighbor of rejuvenated region is due to the satisfaction of elastic adaptability which is resulted by the nanoscale shear events and the induced stress.

Identifying hydrophobic protein patches to inform protein interaction interfaces

Interactions between proteins lie at the heart of numerous biological processes and are essential for the proper functioning of the cell. Although the importance of hydrophobic residues in driving protein interactions is universally accepted, a characterization of protein hydrophobicity, which informs its interactions, has remained elusive. The challenge lies in capturing the collective response of the protein hydration waters to the nanoscale chemical and topographical protein patterns, which determine protein hydrophobicity. To address this challenge, here, we employ specialized molecular simulations wherein water molecules are systematically displaced from the protein hydration shell; by identifying protein regions that relinquish their waters more readily than others, we are then able to uncover the most hydrophobic protein patches. Surprisingly, such patches contain a large fraction of polar/charged atoms and have chemical compositions that are similar to the more hydrophilic protein patches. Importantly, we also find a striking correspondence between the most hydrophobic protein patches and regions that mediate protein interactions. Our work thus establishes a computational framework for characterizing the emergent hydrophobicity of amphiphilic solutes, such as proteins, which display nanoscale heterogeneity, and for uncovering their interaction interfaces.

Determining the water content of nominally anhydrous minerals at the nanometre scale.

The amount and distribution of water in nominally anhydrous minerals (NAMs) are usually determined by Fourier-transform infrared spectroscopy. This method is limited by the spot size of the beam to the study of samples with dimensions greater than a few micrometers. Here, we demonstrate the potential of using photoinduced force microscopy for the measurement of water in NAMs with samples sizes down to the nanometer scale with a study of water concentration across grain boundaries in forsterite. This development will enable the study of water speciation and diffusion in small-grained rock matrixes and allow a determination of the influence of nanoscale heterogeneity on the incorporation of water to NAMs.

Distilling nanoscale heterogeneity of amorphous silicon using tip-enhanced Raman spectroscopy (TERS) via multiresolution manifold learning

Accurately identifying the local structural heterogeneity of complex, disordered amorphous materials such as amorphous silicon is crucial for accelerating technology development. However, short-range atomic ordering quantification and nanoscale spatial resolution over a large area on a-Si have remained major challenges and practically unexplored. We resolve phonon vibrational modes of a-Si at a lateral resolution of <60 nm by tip-enhanced Raman spectroscopy. To project the high dimensional TERS imaging to a two-dimensional manifold space and categorize amorphous silicon structure, we developed a multiresolution manifold learning algorithm. It allows for quantifying average Si-Si distortion angle and the strain free energy at nanoscale without a human-specified physical threshold. The multiresolution feature of the multiresolution manifold learning allows for distilling local defects of ultra-low abundance (< 0.3%), presenting a new Raman mode at finer resolution grids. This work promises a general paradigm of resolving nanoscale structural heterogeneity and updating domain knowledge for highly disordered materials.

Effects of minor Si addition on structural heterogeneity and glass formation of GdDyErCoAl high-entropy bulk metallic glass

Glass-forming ability (GFA) of the Gd20Dy20Er20Co20Al20 high-entropy bulk metallic glass (HE-BMG) was improved through microalloying Si element. The critical diameter of this rare-earth-based HE-BMG increases from 1.5 to 8.5 mm with 0.5 at.% Si addition without any deterioration of magnetocaloric property. Compared with the Si-free sample, the BMG with 0.5 at.% Si addition exhibits low driving force for crystallization, strong supercooled liquid behavior and sluggish crystallization kinetics, whereas excessive Si addition leads to reverse variations. Furthermore, microalloying Si can enhance nanoscale heterogeneity of elemental distribution, and thus facilitates the formation of local crystal-like structures. The connectivity and competition between icosahedra-like clusters and crystal-like structures promote the formation of stable network structure which frustrates crystallization. As Si content is excessive, icosahedra-like cluster is consumed by the further grown crystal-like structure, leading to the destruction of network and decreasing GFA. This work not only elucidates the underlying mechanism of the GFA enhanced by microalloying, but also sheds light on improving the GFA of HE-BMGs through altering nanoscale elemental distribution and structural heterogeneity.

Nanoscale heterogeneity, hydrogen bonding and their temperature dependence in cholinium phenylalaninate bio-ionic liquid

In this article, by employing atomistic molecular dynamics (MD) simulations, we examine the origin of nanoscale structural organization in cholinium phenylalaninate ([Ch][Phe]) biocompatible ionic liquid (IL), in which the [Phe]− anion possesses aromatic ring as its side chain. We attempt to deduce the bulk structure of [Ch][Phe] through simulated X-ray scattering structure function (S(q)), its partial components, real-space correlation functions and hydrogen bond analysis. While the simulated S(q) successfully captures the experimentally observed prepeak, resembling nanoscale heterogeneity, in the S(q) of [Ch][Phe] around q = 0.4 Å−1 at ambient conditions, the temperature dependence of the prepeak in the S(q) shows an unusual behavior. The intensity of the prepeak increases with increasing the temperature, contrary to many imidazolium cation-based ILs, but similar to several ammonium and phosphonium cation-based ILs. Multiple judicial decompositions of the total S(q)s clearly reveal that while [Phe]tail− − [Phe]tail− and [Ch]+ − [Phe]head− correlations are most prominent contributors and indicators of the prepeak, a balance of three major interactions lays down the observation of the nanoscale heterogeneity in this IL. Spatial distribution function analysis also corroborates with these observations, where the segregations of polar groups in polar domains and apolar groups in apolar domains are clearly observed. Our analysis reveals that the increase in the prepeak intensity is because of the increase in all the correlations responsible for the origin of prepeak on increasing the temperature. Hydrogen bond analysis performed through angle-resolved radial distribution functions reveals that only one type of hydrogen bond is present in [Ch][Phe] in which [Ch]+ acts as hydrogen bond donor via its hydroxyl hydrogen and [Phe]− as acceptor via its oxygen atoms. Weakening of this hydrogen bond and enhancement in [Phe]tail− − [Phe]tail− correlation with increasing the temperature are also observed.

Role of Point Defects in the Formation of Relaxor Ferroelectrics

Relaxor ferroelectrics are engineered by doping a large amount of point defects into normal ferroelectrics. The point defects create nanoscale compositional heterogeneity, which in turn lead to local Curie temperature ( T C ) variation and random local electric and strain fields. However, it is still unclear about the individual roles played by each of these effects in converting a normal ferroelectric into a relaxor. In this study we distinguish these effects by carryout computer simulations using the phase field method. We find that although both the local-field and local- T C effects could lead to the formation of nanodomains in relaxors, it is the former that leads to the appearance of Burns temperature T B , the latter that leads to the appearance of the intermediate temperature T *, and a combination of the two allows one to model all three characteristic temperatures of a relaxor reported in experiments: T B , T * and the freezing temperature T f . This work unravels the detailed physical origin of the relaxor behavior and offers deep microscopic insight into relaxors.

Nanoscale chemical speciation of β-amyloid/iron aggregates using soft X-ray spectromicroscopy

Nanoscale resolution X-ray spectromicroscopy shows the co-incubation of β-amyloid (Aβ) and iron(iii) to result in aggregate structures displaying nanoscale heterogeneity in Aβ and iron chemistry, including the formation of potentially cytotoxic Fe0.

Effect of Artificial SEI Content on Lithium Metal Anode Morphology and Performance

Lithium metal is often deemed the “Holy Grail” of rechargeable battery technology, due to its high theoretical capacity and low electrochemical potential. However, the cascading heterogeneity from the formation of the solid-electrolyte interphase (SEI) up to the non-uniform current distribution leads to both poor efficiency via rapid consumption of active materials as well as safety issues from treacherous dendrite growth. An SEI that is ionically conductive while electrically resistive, viscoelastic, electrochemically stable, and possesses good mechanical properties is paramount for hindering these failure mechanisms. The discovery of novel approaches to producing an ideal SEI is a crucial piece to solving the lithium metal anode puzzle.One route of controlling the SEI is through interface engineering by producing a stable artificial SEI. In this work, a mixed artificial SEI was produced with aim toward improving ionic conductivity while retaining electrochemical stability and mechanical properties. This mixed SEI embraces the unavoidable surface heterogeneity, all the while preventing dendrite growth that plagues lithium metal batteries. A mixed artificial SEI, as well as a single-component artificial SEI, were produced through a simple and rapid deposition method and tested to observe their failure mechanisms compared to bare lithium.Symmetric cells (i.e., Li||Li) were utilized to isolate the failure mechanisms of these different anode treatments. The failure mechanism of the single-component artificial SEI cells shifted to failure via electrolyte consumption rather than short circuiting seen with bare lithium. This revealed that artificial interphases led to reduced dendrite propagation. Additionally, a reduction in cell potential range was observed with the mixed artificial SEI when compared to the single-component artificial SEI, as well as improved cyclability. Upon further investigation, it appears that the added component of the mixed artificial SEI, which was meant to improve the ionic conductivity, dissolved into the electrolyte upon initial exposure. This dissolution left behind a new SEI structure, theoretically producing easier ionic pathways and thus resulting in decreased cell overpotential. Dissolution was confirmed with high-resolution surface characterization techniques. Additionally, symmetric cell electrodes rinsed with solvent prior to testing retained superior cell performance. Though this dissolution should lead to increased available “hot spots”, the growth of dendrites was hindered. This work discusses the effect an artificial SEI has on failure mechanisms, as well as provides insight into the methods of producing stable, long-life lithium metal batteries. This includes a focus on how nanoscale heterogeneity effects cell-scale performance via high-resolution characterization and computational simulations.Different surface to sub-surface characterization techniques were utilized to measure properties of artificial SEIs and bare lithium. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS) provided elemental make-up and distribution, as well as morphological characteristics. X-ray photoelectron spectroscopy (XPS) provided the chemical state of surfaces, as well as sub-surfaces with the use of depth profiling. Different atomic force microscopy (AFM) techniques were used to spatially measure nanoscale properties such as work functions with the Kelvin probe technique (SKPFM) and quantifiable nanomechanical properties (QNM), as well as observe kinetic mechanisms with in-situ electrochemical methods (EC-AFM). Lastly, computational simulations from the atomistic scale via density functional theory (DFT) up to molecular dynamics (MD) were utilized to support assumptions on the reaction mechanisms derived from experimental observations. Figure 1

Pore-Scale Water Vapor Condensation Behaviors in Shales: An Experimental Study

Water condensation in shales impacts its hydro-mechanical response. A mechanistic understanding of the pore-water system is made more challenging by significant anisotropy of pore architecture and nano-scale heterogeneity of pore surfaces. We probe the condensation response in two contrasting shales exposed to a vapor of contrast-matching water, as characterized by in situ ultra-small/small-angle neutron scattering (USANS/SANS) techniques under various relative humidities. One shale with a higher content of both kerogen and clay has rougher surfaces and higher anisotropy than the other shale (less clay and no kerogen) over length scales from 2.5 to 250 nm. Scanning electron microscopy with energy-dispersive spectrometry (SEM–EDS) analysis also confirms that the organic-rich shale presents more anisotropic microfabrics and higher heterogeneity compared to the other shale with less clay and no kerogen. USANS/SANS results show that water condensation effectively narrows the pore volume in the way of reducing the aspect ratio of non-equiaxed pores. For the shale with less clays and no kerogen under a relative humidity of 83%, a wetting film uniformly covers the pore-matrix interface over a wide range of length scale (1 nm–1.9 µm) without smoothing the surface roughness. In contrast, for the organic-rich and clay-rich shale with a strong wetting heterogeneity, condensation occurs at strongly curved hydrophilic asperities (1–10 nm) and smoothens the surface roughness. This is consistent with water vapor condensation behavior in a Vosges sandstone by Broseta et al. (Phys. Rev. Lett. 86:5313, 2001). Though well representing the condensation behavior of water vapor in mesopores/macropores (radii > 1 nm), USANS/SANS techniques could underestimate total water adsorption due to potential cation hydration and clay swelling in micropores (radii < 1 nm).

Hopping in High Concentration Electrolytes - Long Time Bulk and Single-Particle Signatures, Free Energy Barriers, and Structural Insights.

Although ion-hopping is believed to be a significant mode of transport for small ions in liquid high concentration electrolytes (HCE), its bulk signatures over sufficiently long time intervals are yet to be shown. We computationally establish the long and short time imprints of hopping in HCEs using LiBF4-in-sulfolane mixtures as models. The high viscosity of this electrolyte leads to significant dynamic heterogeneity in Li-ion transport. Li-ions exhibit a preference to transit to previously occupied Li-ion-sites, bridged through anion or solvent molecules. Hopping in the liquid matrix was found to be an activated process, whose free energy barrier and transition state structure have been determined. Evidence for nanoscale compositional heterogeneity at high salt concentrations is also presented. The simulations shed light on the composition, stiffness, and lifetime of the solvation shell of Li ions. The understanding of HCEs gleaned from this study will spearhead the choice, engineering and applicability of this class of electrolytes.

Probing Nanoscale Diffusional Heterogeneities in Cellular Membranes through Multidimensional Single-Molecule and Super-Resolution Microscopy.

Diffusion properties notably determine the behavior of biomembranes. Here we report the concurrent nanoscale fine-mapping of membrane topography, diffusivity, and packing order in live mammalian cells through a synergy of single-molecule and super-resolution methods. By identifying a bright, lipophilic fluorescence turn-on probe that enables sustained single-molecule imaging of cellular membranes under stroboscopic excitation, we accumulate the positions and transient displacements of >106 probe molecules to achieve super-resolution topography and diffusivity mapping. We thus determine a trend that the membrane diffusivity drops with increased lipid packing order when comparing the endoplasmic reticulum (ER) membrane, plasma membrane, and nanodomains induced by cholera toxin B. Utilizing our nanoscale mapping capability, we further unveil reduced diffusivity in the ER membrane at ER-plasma membrane contact sites. By next integrating spectrally resolved single-molecule imaging, we show that this localized diffusion slowdown is not due to altered lipid packing order but may instead be attributed to local protein crowding. Our integrated multidimensional single-molecule approach thus unveils and differentiates between nanoscale diffusional heterogeneities of different origins in live-cell membranes.

Rapid Structural, Kinetic, and Immunochemical Analysis of Alpha-Synuclein Oligomers in Solution.

Oligomers comprised of misfolded proteins are implicated as neurotoxins in the pathogenesis of protein misfolding conditions such as Parkinson's and Alzheimer's diseases. Structural, biophysical, and biochemical characterization of these nanoscale protein assemblies is key to understanding their pathology and the design of therapeutic interventions, yet it is challenging due to their heterogeneous, transient nature and low relative abundance in complex mixtures. Here, we demonstrate separation of heterogeneous populations of oligomeric α-synuclein, a protein central to the pathology of Parkinson's disease, in solution using microfluidic free-flow electrophoresis. We characterize nanoscale structural heterogeneity of transient oligomers on a time scale of seconds, at least 2 orders of magnitude faster than conventional techniques. Furthermore, we utilize our platform to analyze oligomer ζ-potential and probe the immunochemistry of wild-type α-synuclein oligomers. Our findings contribute to an improved characterization of α-synuclein oligomers and demonstrate the application of microchip electrophoresis for the free-solution analysis of biological nanoparticle analytes.

Structural Heterogeneity, Ductility, and Glass Forming Ability of Zr-Based Metallic Glasses

We show the correlation between nanoscale structural heterogeneity, mechanical property, and glass-forming ability of Zr-Cu-Co-Al metallic glasses (MGs). Local regions with medium-range ordering (MRO) were directly visualized in electron dark-field images of (Zr 45 Cu 50 Al 5 ) 1- x (Zr 55 Co 25 Al 20 ) x MGs acquired using 4-dimensional scanning transmission electron microscopy (4D-STEM), which enables determination of the type, size, and volume fraction of MRO domains with high precision and statistical reliability. Angular correlation analysis of 4D-STEM data shows notable differences in MRO types between x = 0 and x = 1, and certain types of MRO involve structural frustration that correlates to high glass-forming ability. More importantly, the smaller and more diverse MRO at x = 0.5 correlates with a substantial increase in ductility, suggesting a potential role of MRO in the deformation of MGs. Mesoscale deformation simulation incorporating the experimentally determined MRO confirms that the diverse types and sizes of MRO can significantly influence the MGs’ mechanical behavior, which we attribute to the strain frustration mechanism due to increased heterogeneity.

An atomic-level perspective of shear band formation and interaction in monolithic metallic glasses

Understanding the relationship between nanoscale structural heterogeneities or elastic fluctuations and strain localization in monolithic metallic glasses remains a long-standing underlying issue. Here, an atomic-level investigation of the correlation between elastic and structural heterogeneities and the mechanisms of shear banding in CuZr metallic glass is conducted using molecular dynamics simulations. The shear band formation and propagation processes and the intersection mechanism of multiple shear bands are evaluated by means of local entropy-based structural identification and von Mises stress calculation. The shear band follows the path of lower order and high entropy while shear deflection and branching occur when approaching regions of low entropy. The local von Mises stress calculation allows predictions on the shear band direction and the propensity for activation and propagation prior to yielding and sheds light on shear band branching and multiplication processes.