Fundamental Material Properties Research Articles

Real-space observation of ultraconfined in-plane anisotropic acoustic terahertz plasmon polaritons.

Thin layers of in-plane anisotropic materials can support ultraconfined polaritons, whose wavelengths depend on the propagation direction. Such polaritons hold potential for the exploration of fundamental material properties and the development of novel nanophotonic devices. However, the real-space observation of ultraconfined in-plane anisotropic plasmon polaritons (PPs)-which exist in much broader spectral ranges than phonon polaritons-has been elusive. Here we apply terahertz nanoscopy to image in-plane anisotropic low-energy PPs in monoclinic Ag2Te platelets. The hybridization of the PPs with their mirror image-by placing the platelets above a Au layer-increases the direction-dependent relative polariton propagation length and the directional polariton confinement. This allows for verifying a linear dispersion and elliptical isofrequency contour in momentum space, revealing in-plane anisotropic acoustic terahertz PPs. Our work shows high-symmetry (elliptical) polaritons on low-symmetry (monoclinic) crystals and demonstrates the use of terahertz PPs for local measurements of anisotropic charge carrier masses and damping.

Direct Observation of Group-V Dopant Substitutional Defects in CdTe Single Crystals.

Point defect chemistry strongly affects the fundamental properties of materials and has a decisive impact on device performance. The Group-V dopant is prominent acceptor species with high hole concentration in CdTe; however, its local atomic structure is still not clear owing to difficulties in definitive measurements and discrepancies between experimental observations and theoretical models. Herein, we report on direct observation of the local structure for the As dopant in CdTe single crystals by the X-ray fluorescence holography (XFH) technique, which is a powerful tool to visualize three-dimensional atomic configurations around a specific element. The XFH result shows the As substituting on both Cd (AsCd) and Te (AsTe) sites. Although AsTe has been well known as a shallow acceptor, AsCd has not attracted much attention and been discussed so far. Our results provide new insights into point defects by expanding the experimental XFH study in combination with theoretical first-principles studies in II-VI semiconductors.

Design of hierarchical microstructures with isotropic elastic stiffness

Elastic stiffness is one of the most fundamental properties of materials. Design of the microstructures with isotropic stiffness has been an attractive area in the field of metamaterials for over three decades. Despite many classes of isotropic microstructures, exploring novel isotropic microstructures based on innovative mechanics principles has attracted great and continuing interests. This paper presents a novel family of isotropic hierarchical microstructures (Iso-HMs). These hierarchical microstructures are modeled by replacing the solid parts of prescribed single-level microstructures with arrayed microstructures in the second level, where the key task is to identify the correct geometries of the second-level microstructures by conducting parameter space exploring. These Iso-HMs realize isotropic stiffness based on synergistic deformations of the members in the two levels, which is essentially different from existing isotropic microstructures replying on deformations of the members in a single level. Two categories of Iso-HMs with rectangular holes and Vidergauze-type struts are designed. Considering the large size difference in the designed Iso-HMs, additive manufacturing becomes a unique technique for manufacturing the designed Iso-HMs, where the size ratio between the 3D-printed specimens and the minimal features reaches 400:1. Both numerical and experimental results validate the isotropic stiffness of the designed Iso-HMs. Furthermore, the results of a microstructural instability analysis show that the designed Iso-HMs can gain improved buckling strength up to a hundred times higher than their single-level counterparts. The hierarchical design provides a new way to identify novel functional microstructures for applications, and the hierarchical configurations expand the space of the already-known families of isotropic microstructures.

Research Progress of Green Solvent in CsPbBr3 Perovskite Solar Cells.

In optoelectronic applications, all-Brominated inorganic perovskite CsPbBr3 solar cells have received a great deal of attention because of their remarkable stability and simplicity of production. Most of the solvents used in CsPbBr3 perovskite solar cells are toxic, which primarily hinders the commercialization of the products. In this review, we introduce the crystal structure and fundamental properties of CsPbBr3 materials and the device structure of perovskite cells, summarize the research progress of green solvents for CsPbBr3 PSCs in recent years from mono-green solvent systems to all-green solvent systems, and discuss the approaches to improving the PCE of CsPbBr3 PSCs, intending to facilitate the sustainable development of CsPbBr3 perovskite solar cells. Finally, we survey the future of green solvents in the area of CsPbBr3 perovskite solar cells.

Probing the dipole–dipole interaction in single 0D/2D heterostructures by tightly focused cylindrical vector beams

Energy transfer from zero-dimensional (0D) quantum dots (QDs) to two-dimensional (2D) materials has attracted much attention for both the manipulation of fundamental material properties and their potential device applications. An understanding of the effect of dipole interactions on energy transfer rate in the hybrid dimensional system is essential for improving optoelectronic device performance. Here, we report the dipole-orientation-dependent energy transfer from individual core–shell CdSe/ZnS QDs to bilayer molybdenum disulfide (MoS2) by utilizing tightly focused azimuthally and radially polarized cylindrical vector beams. With second-order photon correlation measurements [g2(τ)], we show the single-photon emission behavior from QDs in 0D/2D heterostructures, indicating that the investigated heterostructure is constructed from single QDs. By polarization resolved photoluminescence (PL) imaging and PL lifetime measurements, we observe a fast energy transfer rate of the system excited with azimuthally polarized beams and interpret it based on dipole–dipole interactions with Förster energy transfer theory. Our work provides an in-depth understanding of the dipole-orientation-dependent energy transfer mechanism in 0D/2D systems, which could offer guidance for designing the related optoelectronic device applications.

Exchange stiffness constant determination using multiple-mode FMR perpendicular standing spin waves

The exchange stiffness constant is recognized as one of the fundamental properties of magnetic materials, though its accurate experimental determination remains a particular challenge. In thin films, resonance measurements exploiting perpendicular standing spin waves (PSSWs) are increasingly used to extract this parameter, typically through a determination of the first-order PSSW mode. Here, we present a systematic study of multiple PSSW modes in NiFe films, where both the sample thickness and the cap layer material are varied. The results show that a simple analysis based on the Kittel rigid pinning model yields an exchange stiffness constant that varies with thickness, mode number, and capping layer material. This finding is clearly inconsistent with physical expectation that the exchange stiffness constant of a material is single valued for a particular set of thermodynamic conditions. Using a more general exchange boundary condition, we show, through a comprehensive set of micromagnetic simulations, that a dynamic pinning mechanism originally proposed by Wigen is able to reproduce the experimental results using a single value of Aex. Our findings support the utility of short wavelength, higher order PSSWs to determine the Aex of thin films and show that the value of Aex obtained has a weak dependency on the material immediately adjacent to the magnetic layer.

Neural modulation with photothermally active nanomaterials

Modulating neural electrophysiology with high precision is essential for understanding neural communication and for the diagnosis and treatment of neural disorders. Photothermal modulation offers a remote and non-genetic method for neural modulation with high spatiotemporal resolution and specificity. This technique induces highly localized and transient temperature changes at the cell membrane interfaced with photothermally active nanomaterials. This rapid temperature change affects the electrical properties of the cell membrane or temperature-sensitive ion channels. In this Review, we discuss the fundamental material properties and illumination conditions that are necessary for nanomaterial-assisted photothermal neural excitation and inhibition. We examine how this versatile technique allows direct investigation of neural electrophysiology and signalling pathways in two-dimensional and three-dimensional cell cultures and tissues, and highlight the scientific and technological challenges in terms of cellular specificity, light delivery and biointerface stability on the road to clinical translation. Photothermal modulation is a non-genetic approach for remote neural modulation with high spatiotemporal resolution and specificity. This Review summarizes the fundamental material properties and experimental conditions necessary for efficient nanomaterial-assisted photothermal excitation, inhibition and regulation of cellular signalling pathways.

Charge transport and acoustic loss in lithium niobate-lithium tantalate solid solutions at temperatures up to 900 °C

Polar oxides, in particular solid solutions of lithium niobate and lithium tantalate (LNT, LiNb1-xTaxO3) are a variable model system to study fundamental materials properties due to miscibility of the edge compounds lithium niobate (LN, LiNbO3) and lithium tantalate (LT, LiTaO3) as well as tunable domain structures. Further new applications in the field of high-temperature actuators are aimed as LNT crystals potentially combine the advantages of the edge compounds with respect to high thermal stability and high piezoelectric coefficients. Beside LN and LT, LNT crystals of two compositions (LiNb0.88Ta0.12O3 and LiNb0.5Ta0.5O3) were grown by the Czochralski technique. Electrical conductivity, lithium diffusion and acoustic loss of LNT at high temperatures were investigated and correlated. Two techniques, namely impedance spectroscopy and resonant piezoelectric spectroscopy (RPS) are applied in this investigation. The electrical conductivity of investigated samples increases linearly in an Arrhenius presentation up to ∼605 °C. After a transition range of 605–620 °C, the conductivity increases linearly again for LT, but the slope is decreased by about 0.15 eV. This indicates that the conductivity below and above the Curie temperature is governed by a slightly different process. In contrast, LN shows a gradually increasing slope in the Arrhenius representation above the transition temperature range mentioned above. Here, a single activation energy cannot be assigned. The increase can be explained by the limited thermal stability of LN at elevated temperatures. Further, the acoustic loss in LNT thickness-shear mode resonators operated at about 2 and 10 MHz is determined by RPS and found to strongly increase above about 450 °C. In addition, the acoustic loss is modelled using independent materials data including electrical conductivity as determined here, and found to be in excellent agreement with the RPS data for the 10 MHz resonator. Based on the modelling, the loss above 450 °C is governed by conductivity-induced piezoelectric/carrier relaxation which can be attributed to lithium migration.

First-principles study of the temperature-induced band renormalization in thermoelectric filled skutterudites.

Band structure characteristics, such as band gap and band dispersion, are fundamental properties of materials. Temperature can affect them because of lattice expansion and phonon-induced atomic vibrations. Here, we apply the recently developed electron-phonon renormalization method to study the temperature effect on the band structures of thermoelectric (TE) filled skutterudites BaCo4Sb12, BaFe4Sb12, and YbFe4Sb12 from first-principles. The results reveal that the band gap in BaCo4Sb12 drops slower with temperature compared with our previous study on CoSb3, where it considerably reduces from 0 K to 800 K for BaFe4Sb12 (∼0.222 eV) and YbFe4Sb12 (∼0.201 eV). Furthermore, the band dispersions near the band edges at the Γ-point in the three systems at high temperatures are similar to those at 0 K, and the electron energies have small linewidths, whereas the linewidths for energies near the Fermi level are large. The different phenomena are due to the different phonon vibration-induced electronic structure disorders, reflecting the strength of electron-phonon coupling. Band renormalization would further affect the TE properties of these filled skutterudites. Our work provides a deeper understanding of the temperature-dependent band structure in skutterudites.

Structure and Physical Property Control of Polymer Materials using Various Mechanical Tests and <i>in situ</i> Multiscale Structure Analyses

The goal of our research group is to understand fundamental structure and properties of polymer materials and to develop new ones. We deal with versatile polymer materials including rubbers, crystalline and amorphous plastics. Molecular aggregation structure and mechanical, thermal, optical, electrical, and adhesive properties have been investigated combining various mechanical deformation modes and in situ multiscale structure analyses such as small-angle and wide-angle X-ray scattering (SAXS/WAXS) measurements, polarized optical microscopic observation, vibrational spectroscopy. Concrete research topics are (1) network and microphase-separated structure analyses of styrenic triblock thermoplastic elastomer, and polyurethane under uniaxial/biaxial/bulge deformation, (2) change in molecular aggregation structure of polycarbonate, and poly (methyl methacrylate) under uniaxial/biaxial/bulge deformation, (3) analysis of local mechanical property of polymers using synchrotron X-ray beam, and high-speed polarized optical microscopic observation, (4) adhesive and fatigue properties of epoxy, and polyurethanes.

Evaluation of the Unsaturated Shear Strength Parameters of Compacted, Heaving Soil Using Geotechnical Properties

Abstract The shear strength is a fundamental property of soil material under structural loads. The determination of shear strength properties of unsaturated soils is challenging and time-consuming. Geotechnical predictive models can be utilized to assess the unsaturated shear strength of heaving soil. This study attempts to propose predictive models to evaluate the unsaturated shear strength parameters of compacted heaving soil. These parameters include the angle of internal friction associated with the net normal stress (ϕ'), angle indicating the rate of increase in shear strength with respect to a change in matric suction (ϕb), and effective cohesion (c'). The geotechnical properties of soils were assessed through laboratory tests such as particle size distribution, consistency limits, specific gravity, modified Proctor compaction test, swelling test, suction test, and advanced triaxial testing. Multivariate analysis was conducted using NCSS 12 software to design the models. The validation of models includes the determination coefficient, probability value, comparing experimental values with predicted values, and comparing the developed models with other model found in recent literature. The models engineered in this study can estimate the unsaturated shear strength parameters of compacted heaving soil with acceptable precision.

Accomodation of deformation in rolled Aluminium

The current as well as the future industrial market for Aluminium (Al) is huge and various research is being under work regarding the usability of Aluminium. However, during the deep drawing of Aluminium several issues can be developed and some of them are originated from the fundamental material properties. One of these factors is the material texture, which is the preferred orientation of the constituent polycrystalline Al, and the characteristic texture is affected by different rolling and annealing schedules. To investigate the material texture, symmetric and asymmetric rolling trials were performed on a commercially available Al 1050 sample. Energy-dispersive X-ray Spectroscopy (EDX), and Electron Backscatter Diffraction (EBSD) scanning has performed to determine the material composition and the crystallographic orientations of the investigated samples.

Electro-modulation and surface photovoltage spectroscopy with semi-transparent graphene electrodes

Investigating the fundamental properties of new semiconductor materials and structures requires the use of a wide range of optical spectroscopy techniques. Among them, there are those that exploit the use of electrodes that are semi-transparent to light, a requirement arising from the need to either apply external perturbation to the studied material or sense the effects generated by light excitation. In this work, semi-transparent graphene electrodes were obtained by chemical vapour deposition of the graphene on a copper substrate and transferring these layers to a sapphire substrate. The fabricated electrodes were tested in contactless electroreflectance, soft-contact electroreflectance, and surface photovoltage spectroscopy on III-V epilayers (InP and GaAs) and van der Waals crystals (MoS2 and WSe2), reference industry-standard and emerging semiconductors. The obtained results clearly show that graphene electrodes are suitable for these measurements and have many advantages over the commonly used approaches to ensure transparent conducting layers in optoelectronic devices. On the other hand, compared to indium‑tin oxide, their transparency covers a wide spectral range, including ultraviolet (UV), revealing another important advantage. We also demonstrate that further structuring of the graphene layer enables maximizing the transparency up to the limit imposed by the hosting substrate.

The Estimation of Taylor-Quinney Coefficients Using Small Ring Specimens

BackgroundThe use of the Taylor-Quinney coefficient for introducing a thermal dissipation term into material models relies on understanding its dependencies. These are usually determined through extensive experimentation, wherein temperature variations are monitored in a test piece during mechanical loading.ObjectiveThis study aims to reduce the cost and time necessary to determining the dependencies of the Taylor-Quinney coefficient by proposing a novel small specimen inverse testing method and demonstrating its use on aluminium alloy 7175.MethodsThe method proposed is based on mechanical testing of a novel small ring specimen in parallel with FEA simulations. In the experiments, small rings of 7175-T7351 aluminium alloy, 20 mm in outer diameter, were loaded between two pins for different pin displacement rates (namely 1, 1.5 and 2 mm/s) at room temperature and the local specimen temperature field was monitored using an infra-red thermal camera. Fully coupled thermal-mechanical simulations of the tests were performed using a range of Taylor-Quinney coefficients, and the resulting temperature evolutions compared to the experimental results in order to determine appropriate coefficient values for the material.ResultsThe method presented shows good repeatability and allows for clear observation of thermal dissipation. Taylor-Quinney values ranging 0.51-0.59 are reported for the 7175 alloy, in line with values reported in the literature for similar alloys. Density, specific heat capacity and thermal conductivity, fundamental thermal material properties necessary for the simulations, are also reported for the alloy.ConclusionsThe method detailed shows promise for determining Taylor-Quinney coefficients in a wide range of experimental conditions and is proposed as a cheap and fast alternative to full-scale specimen testing of Taylor-Quinney coefficients. Taylor-Quinney values obtained for 7175 aluminium are shown to be much lower than the value of 0.9 often proposed for materials.

PULSEE: A software for the quantum simulation of an extensive set of magnetic resonance observables

We present an open-source software for simulation of observables in magnetic resonance experiments, including nuclear magnetic/quadrupole resonance NMR/NQR and electron spin resonance (ESR). Inspired by magnetic resonance protocols that emerged in the context of quantum information science (QIS), this software can assist experimental research in the design of new strategies for the investigation of fundamental quantum properties of materials. The package introduced here can simulate both standard NMR spectroscopic observables and the time-evolution of an interacting single-spin system subject to complex pulse sequences, i.e. quantum gates. The main purpose of this software is to facilitate the development of much needed novel NMR-based probes of emergent quantum order, which can be elusive to standard experimental probes. The software is based on a quantum mechanical description of nuclear spin dynamics in NMR/NQR experiments and has been widely tested on available theoretical and experimental results. Moreover, the structure of the software allows for basic experiments to be easily generalized to more sophisticated ones because it includes all the libraries required for the numerical simulation of generic spin systems. In order to make the program easily accessible to a large user base, we developed a user-friendly graphical interface, Jupyter notebooks, and fully-detailed documentation. Lastly, we portray several examples of the execution of the code that illustrate the prosepcts of a novel NMR paradigm, inspired by QIS, for efficient investigation of emergent phases in strongly correlated materials. Program summaryProgram Title: PULSEE (Program for the simULation of nuclear Spin Ensemble Evolution)CPC Library link to program files:https://doi.org/10.17632/vvv8tcb2nt.1Developer's repository link:https://github.com/vemiBGH/PULSEELicensing provisions: GPLv3Programming language: Python 3Nature of problem: Application of nuclear magnetic/quadrupole resonance techniques to study properties of materials often requires extensive spectral simulations. On the other hand, application of magnetic resonance techniques to quantum information science (QIS) involves different sets of observables. Available simulation software addresses only one of these applications: either detailed spectral simulations [1] or QIS relevant observables [2]. For this reason, NMR has not seen as much development in the condensed matter community compared to other spectroscopic techniques that combine these two approaches. Therefore, there is a need for an up-to-date and easily accessible software that can simulate an extensive set of NMR/NQR experimental observables, reproducing the behavior/response of nuclear systems with a varying degree of complexity encountered in strongly correlated quantum materials.Solution method: The open-source Python code provides an extensive set of libraries for the simulation of spin time evolution in the presence of specific interactions and reproduction of spectra; as well as other observables measured in magnetic resonance experiments; and simulations of quantum circuits and gates. The ready-to-use software features a user-friendly graphical interface, and Jupyter notebooks.

Ultrahigh Carrier Mobility in Cd3As2 Nanowires

Magnetotransport measurements are carried out on nanowires of the Dirac semimetal . Weak antilocalization is observed at 1.9 K, consistent with the presence of strong spin–orbit interaction. With decreasing temperature, Shubnikov–de Haas oscillations are seen, revealing an ultrahigh mobility of 57 000 cm2 Vs at 1.9 K. The strong oscillations display a linear dependence of the Landau‐level index on the inverse of the magnetic field, yielding an intercept that is consistent with a π Berry phase—the signature feature of Dirac fermions. By studying the fundamental properties of Dirac materials, new avenues can be explored by exploiting their unique properties for spintronics and magnetoelectronic devices.

Platinum group metal-free Fe−N−C catalysts for PEM fuel cells derived from nitrogen and sulfur doped synthetic polymers

• PGM-free Fe−N−C catalysts are produced from N or N/S co-doped porous organic gels. • S-doping alters fundamental properties of carbon materials vs S-free counterparts. • S co-doping induces extensive ultramicroporosity (pores of ∼0.6 nm) • Ultramicropores could enhance ORR via their strong adsorption potential. • S co-doped Fe−N−C catalysts achieve ∼0.15 W cm −2 peak power density in a H 2 –air FC. • Morphology dominates other Fe−N−C characteristics and determines FC performance. Fe−N−C electrocatalysts were obtained via pyrolysis of N- or N/S co-doped synthetic polymers impregnated with FeCl 3 . The influence of the presence/absence of sulfur co-doping, the initial FeCl 3 content and phenanthroline addition on the Fe−N−C–based cathode catalyst layers (CCLs) performance in H 2 -air PEM fuel cells was studied. To this end the Fe−N−C materials were first characterized concerning their chemical composition, surface chemistry, porosity and morphology. Sulfur and phenanthroline additions strongly affect these characteristics of Fe−N−C materials. This in turn determines (to various extents) the electrochemical properties as measured with a rotating ring-disk electrode and upon infusion in the cathode catalyst layer in H 2 -air PEM fuel cells. While simultaneous sulfur and phenanthroline addition yields Fe−N−C catalysts with high N-content and specific surface area, this does not translate into good electrochemical performance. We discuss the multitude of factors determining the catalysts’ and the final CCLs’ performances and conclude that the specific micro-colloidal morphology of the carbon gel-based materials dominates other Fe−N−C characteristics and determines overall FC performance. The best performing CCL provided peak power density of ∼0.15 W⋅cm −2 in a H 2 -air PEMFC.

Combined Experimental and Simulation Studies of Lithium and Cobalt‐Modified TiO2 and Their Impacts on the Performance and Stability of Perovskite Solar Cells (Adv. Mater. Interfaces 31/2022)

Photovoltaic Performance Stability The most fundamental properties of photovoltaic materials are impacted by the photoinduced charge separation behavior, which can be improved by modifying the underlying layer that the perovskite is prepared on top. In article number 2201632, Non Thongprong, Nopporn Rujisamphan, and colleagues investigate the impacts of using alkali salts on porous TiO2 from experimental and computational points of view to provide a better understanding of such surface passivation.

Biaxial mechanical properties of the bronchial tree: Characterization of elasticity, extensibility, and energetics, including the effect of strain rate and preconditioning

Distal airways commonly obstruct in lung disease and despite their importance, their mechanical properties are vastly underexplored. The lack of bronchial experiments restricts current airway models to either assume rigid structures, or extrapolate the material properties of the trachea to represent the small airways. Furthermore, past works are exclusively limited to uniaxial testing; investigating the multidirectional tensile loads of both the proximal and distal pulmonary airways is long overdue. Here we present comprehensive mechanical and viscoelastic properties of the porcine airway tree, including the trachea, trachealis muscle, large bronchi, and small bronchi, via measures of elasticity, extensibility, and energetics to explore regional and directional dependencies, cross-examining strain rate and preconditioning effects using planar equibiaxial tensile tests for the first time. We find bronchial regions are notably heterogeneous, where the trachea exhibits greater stiffness, energy loss, and preconditioning sensitivity than the smaller airways. Interestingly, the trachealis muscle is similar to the distal bronchi, despite being anatomically located adjacent to the proximal ring. Tissues are anisotropic and axially stiffer under initial loading, losing more energy with greater stress relaxation circumferentially. Strain rate dependency is also noted, where tissues are more energetically efficient at the faster strain rate, likely attributable to the microstructure. Findings highlight assumptions of homogeneity and isotropy are inadequate, and enable the improvement of aerosol flow and dynamic airway deformation computational predictive models. These results provide much needed fundamental material properties for future explorations contrasting healthy versus diseased pulmonary airway mechanics to better understand the relationship between structure and lung function. Statement of significanceWe present comprehensive multiaxial mechanical tensile experiments of the proximal and distal airways via measures of maximum stress, initial and ultimate moduli, strain and stress transitions, hysteresis, energy loss, and stress relaxation, and further assess preconditioning and strain rate dependencies to examine the relationship between lung function and structure. The mechanical response of the bronchial tree demonstrates significant anisotropy and heterogeneity, even within the tracheal ring, and emphasizes that contrary to past studies, the behavior of the proximal airways cannot be extended to distal bronchial tree analyses. Establishing these material properties is critical to advancing our understanding of airway function and in developing accurate computational simulations to help diagnose and monitor pulmonary diseases.

Molecular Dynamics Simulation for Thiolated Poly(ethylene glycol) at Low‐Temperature Based on the Density Functional Tight‐Binding Method

AbstractThe condensed structure of a material is the basis for the properties of polymeric materials, where the crystalline structure is the most ordered conformation of the polymer condensed structure. The mechanical properties are one of the most fundamental properties of polymer materials and the crystalline state has an important influence on the mechanical properties. Here, the optimal chain conformation and the effect of optimization time on the temperature and energy of molecular thermodynamics and molecular dynamics are investigated using thiolated poly(ethylene glycol) as the base material. The simulation results show that the number of optimization steps and the simulation time are closely related to the molecular conformation of polymer single crystals. A new perspective is provided for exploring intra‐ and intermolecular interactions in polymer crystals and revealing their nature, establishing the link between chain structure and mechanical properties of materials, and designing and manufacturing polymer crystalline materials with better mechanical properties.