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At least 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Li2Fe2(WO4)3 by Materials Project

Li2Fe2(WO4)3 crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with four WO4 tetrahedra and edges with two equivalent FeO6 octahedra. There are a spread of Li–O bond distances ranging from 1.98–2.03 Å. There are two inequivalent W+5.33+ sites. In the first W+5.33+ site, W+5.33+ is bonded to four O2- atoms to form WO4 tetrahedra that share corners with four equivalent FeO6 octahedra and corners with three equivalent LiO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 18–49°. There are a spread of W–O bond distances ranging from 1.79–1.83 Å. In the second W+5.33+ site, W+5.33+ is bonded to four O2- atoms to form WO4 tetrahedra that share corners with four equivalent FeO6 octahedra and corners with two equivalent LiO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 22–40°. There is two shorter (1.80 Å) and two longer (1.83 Å) W–O bond length. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six WO4 tetrahedra and edges with two equivalent LiO4 trigonal pyramids. There are a spread of Fe–O bond distances ranging from 2.08–2.21 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one W+5.33+, and one Fe3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one W+5.33+, and one Fe3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one W+5.33+, and one Fe3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one W+5.33+, and one Fe3+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one W+5.33+ and one Fe3+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one W+5.33+ and one Fe3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr9W4O3 by Materials Project

Zr9W4O3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Zr sites. In the first Zr site, Zr is bonded in a distorted bent 150 degrees geometry to two equivalent W and two equivalent O atoms. Both Zr–W bond lengths are 2.95 Å. Both Zr–O bond lengths are 2.26 Å. In the second Zr site, Zr is bonded in a 2-coordinate geometry to four W and two equivalent O atoms. There are a spread of Zr–W bond distances ranging from 3.07–3.17 Å. Both Zr–O bond lengths are 2.36 Å. There are two inequivalent W sites. In the first W site, W is bonded in a 12-coordinate geometry to eight Zr and four W atoms. There are two shorter (2.72 Å) and two longer (2.88 Å) W–W bond lengths. In the second W site, W is bonded to six equivalent Zr and six equivalent W atoms to form WZr6W6 cuboctahedra that share edges with six equivalent OZr6 octahedra and faces with two equivalent WZr6W6 cuboctahedra. O is bonded to six Zr atoms to form OZr6 octahedra that share corners with six equivalent OZr6 octahedra and edges with two equivalent WZr6W6 cuboctahedra. The corner-sharing octahedra tilt angles range from 37–43°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf9W4Se by Materials Project

Hf9W4Se crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 1-coordinate geometry to four W and one Se atom. There are a spread of Hf–W bond distances ranging from 2.87–3.09 Å. The Hf–Se bond length is 2.75 Å. In the second Hf site, Hf is bonded in a distorted T-shaped geometry to two equivalent W and one Se atom. Both Hf–W bond lengths are 2.94 Å. The Hf–Se bond length is 3.17 Å. There are two inequivalent W sites. In the first W site, W is bonded in a 12-coordinate geometry to eight Hf and four W atoms. There are two shorter (2.73 Å) and two longer (2.89 Å) W–W bond lengths. In the second W site, W is bonded to six equivalent Hf and six equivalent W atoms to form face-sharing WHf6W6 cuboctahedra. Se is bonded in a 9-coordinate geometry to nine Hf atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ReW4 by Materials Project

W4Re crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. there are two inequivalent W sites. In the first W site, W is bonded in a 8-coordinate geometry to two equivalent W and two equivalent Re atoms. Both W–W bond lengths are 2.75 Å. Both W–Re bond lengths are 2.74 Å. In the second W site, W is bonded in a distorted body-centered cubic geometry to eight W atoms. All W–W bond lengths are 2.75 Å. Re is bonded in a 4-coordinate geometry to four equivalent W atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ReW3 by Materials Project

W3Re crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent W sites. In the first W site, W is bonded in a 8-coordinate geometry to two equivalent W and two equivalent Re atoms. Both W–W bond lengths are 2.75 Å. Both W–Re bond lengths are 2.74 Å. In the second W site, W is bonded in a distorted body-centered cubic geometry to eight W atoms. All W–W bond lengths are 2.74 Å. Re is bonded in a 4-coordinate geometry to four equivalent W atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf9W4S by Materials Project

Hf9W4S crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 1-coordinate geometry to four W and one S atom. There are a spread of Hf–W bond distances ranging from 2.89–3.09 Å. The Hf–S bond length is 2.68 Å. In the second Hf site, Hf is bonded in a distorted T-shaped geometry to two equivalent W and one S atom. Both Hf–W bond lengths are 2.91 Å. The Hf–S bond length is 3.14 Å. There are two inequivalent W sites. In the first W site, W is bonded in a 12-coordinate geometry to eight Hf and four W atoms. There are two shorter (2.72 Å) and two longer (2.89 Å) W–W bond lengths. In the second W site, W is bonded to six equivalent Hf and six equivalent W atoms to form face-sharing WHf6W6 cuboctahedra. S is bonded in a 6-coordinate geometry to nine Hf atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf9CoW4 by Materials Project

Hf9W4Co crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 1-coordinate geometry to four W and one Co atom. There are a spread of Hf–W bond distances ranging from 2.94–3.09 Å. The Hf–Co bond length is 2.56 Å. In the second Hf site, Hf is bonded in a 2-coordinate geometry to two equivalent W atoms. Both Hf–W bond lengths are 2.89 Å. There are two inequivalent W sites. In the first W site, W is bonded in a 12-coordinate geometry to eight Hf and four W atoms. There are two shorter (2.71 Å) and two longer (2.93 Å) W–W bond lengths. In the second W site, W is bonded to six equivalent Hf and six equivalent W atoms to form face-sharing WHf6W6 cuboctahedra. Co is bonded in a 6-coordinate geometry to six equivalent Hf atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al3Co(W3C)3 by Materials Project

W9Al3CoC3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent W sites. In the first W site, W is bonded in a 2-coordinate geometry to one Co, three equivalent Al, and two equivalent C atoms. The W–Co bond length is 2.85 Å. There are two shorter (2.80 Å) and one longer (2.83 Å) W–Al bond lengths. Both W–C bond lengths are 2.16 Å. In the second W site, W is bonded in a distorted rectangular see-saw-like geometry to two equivalent Al and two equivalent C atoms. Both W–Al bond lengths are 2.66 Å. Both W–C bond lengths are 2.09 Å. Co is bonded to six equivalent W and six equivalent Al atoms to form CoAl6W6 cuboctahedra that share edges with six equivalent CW6 octahedra, faces with two equivalent CoAl6W6 cuboctahedra, and faces with six equivalent AlAl2Co2W8 cuboctahedra. All Co–Al bond lengths are 2.48 Å. Al is bonded to eight W, two equivalent Co, and two equivalent Al atoms to form distorted AlAl2Co2W8 cuboctahedra that share corners with four equivalent AlAl2Co2W8 cuboctahedra, corners with four equivalent CW6 octahedra, faces with two equivalent CoAl6W6 cuboctahedra, faces with six equivalent AlAl2Co2W8 cuboctahedra, and faces with four equivalent CW6 octahedra. The corner-sharing octahedral tilt angles are 39°. Both Al–Al bond lengths are 2.63 Å. C is bonded to six W atoms to form CW6 octahedra that share corners with four equivalent AlAl2Co2W8 cuboctahedra, corners with six equivalent CW6 octahedra, edges with two equivalent CoAl6W6 cuboctahedra, and faces with four equivalent AlAl2Co2W8 cuboctahedra. The corner-sharing octahedra tilt angles range from 40–46°.

36 MATERIALS SCIENCE↗
DOE OSTI2024

High‐Pressure Synthesis of Ultra‐Incompressible, Hard and Superconducting Tungsten Nitrides

Abstract Transition metal nitrides, particularly those of 5 d metals, are known for their outstanding properties, often relevant for industrial applications. Among these metal elements, tungsten is especially attractive given its low cost. In this high‐pressure investigation of the W–N system, two novel ultra‐incompressible tungsten nitride superconductors, namely W 2 N 3 and W 3 N 5 , are successfully synthesized at 35 and 56 GPa, respectively, through a direct reaction between N 2 and W in laser‐heated diamond anvil cells. Their crystal structure is determined using synchrotron single‐crystal X‐ray diffraction. While the W 2 N 3 solid's sole constituting nitrogen species are N 3‐ units, W 3 N 5 features both discrete N 3‐ as well as N 2 4‐ pernitride anions. The bulk modulus of W 2 N 3 and W 3 N 5 is experimentally determined to be 380(3) and 406(7) GPa, and their ultra‐incompressible behavior is rationalized by their constituting WN 7 polyhedra and their linkages. Importantly, both W 2 N 3 and W 3 N 5 are recoverable to ambient conditions and stable in air. Density functional theory calculations reveal W 2 N 3 and W 3 N 5 to have a Vickers hardness of 30 and 34 GPa, and superconducting transition temperatures at ambient pressure (50 GPa) of 11.6 K (9.8 K) and 9.4 K (7.2 K), respectively. Additionally, transport measurements performed at 50 GPa on W 2 N 3 corroborate with the calculations.

Chemistry↗
DOE OSTI2021

In situ synchrotron X-ray imaging and mechanical properties characterization of additively manufactured high-entropy alloy composites

Laser beam directed energy deposition has become an increasingly popular advanced manufacturing technique for materials discovery as a result of the in situ alloying capability. In this study, we leverage an additive manufacturing enabled high throughput materials discovery approach to explore the composition space of a graded W x (CoCrFeMnNi) 100–x sample spanning 0 ≤ x ≤ 21 at%. In addition to microstructural and mechanical characterization, synchrotron high speed x-ray computer aided tomography was conducted on a W 20 (CoCrFeMnNi) 80 composition to visualize melting dynamics, powder-laser interactions, and remelting effects of previously consolidated material. Results reveal the formation of the Fe 7 W 6 intermetallic phase at W concentrations> 6 at%, despite the high configurational entropy. Unincorporated W particles also occurred at W concentrations> 10 at% accompanied by a dissolution band of Fe 7 W 6 at the W/matrix interface and hardness values greater than 400 HV. In this work, the primary strengthening mechanism is attributed to the reinforcement of the Fe 7 W 6 and W phases as a metal matrix composite. The in situ high speed x-ray imaging during remelting showed that an additional laser pass did not promote further mixing of the Fe 7 W 6 or W phases suggesting that, despite the dissolution of the W into the Fe 7 W 6 phase being thermodynamically favored, it is kinetically limited by the thickness/diffusivity of the intermetallic phase, and the rapid solidification of the laser-based process.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Molybdenum and Tungsten isotope compositions of UO 2 fuel pellets: Implications for isotopically enriched taggants

The addition of isotopically enriched taggants to material at the front end of the nuclear fuel cycle could be a powerful tool used to assist law enforcement authorities should material outside of regulatory control be found. Two potential candidates for this purpose are molybdenum (Mo) and tungsten (W) as both elements have five or more stable isotopes and are trace elements contained within nuclear fuel. So there is a concern that Mo and W could undergo isotope fractionation during processes like uranium enrichment and to date, it is unknown if nuclear fuels have natural Mo and W isotope compositions. If Mo and W isotopic variability is present in nuclear fuels, this would hinder the use of these elements as isotopic taggants because it would be difficult to discern the original taggant isotope composition with high confidence. Therefore, a set of 16 low enriched uranium (LEU) fuel pellets from US commercial producers was analyzed using multi collector-inductively coupled plasma mass spectrometry (MC-ICPMS) to determine Mo and W isotope compositions (i.e., 94 Mo/ 92 Mo, 95 Mo/ 92 Mo, 96 Mo/ 92 Mo, 97 Mo/ 92 Mo, 98 Mo/ 92 Mo, 183 W/ 182 W, 184 W/ 182 W, and 186 W/ 182 W). Relative to terrestrial standards, LEU fuel pellets have variable Mo and W isotope compositions, thereby complicating the use of these elements as isotopically enriched taggants. As such, this work demonstrates that the isotope composition of any potential taggant must be well characterized in the base nuclear fuel prior to any taggant addition. Furthermore, these results suggest that Mo and W are not ideal candidates for isotopically enriched taggants.

58 GEOSCIENCES↗
DOE OSTI2024

Assessing observational constraints on dark energy

Observational constraints on time-varying dark energy (e.g., quintessence) are commonly presented on a w 0 –w a plot that assumes the equation of state of dark energy strictly satisfies w(z) = w 0 + w a z/(1 + z) as a function of the redshift z. Recent observations favor a sector of the w 0 –w a plane in which w 0 > –1 and w 0 + w a < –1, suggesting that the equation of state underwent a transition from violating the null energy condition (NEC) at large z to obeying it at small z. In this paper, we demonstrate that this impression is misleading by showing that simple quintessence models satisfying the NEC for all z predict an observational preference for the same sector. We also find that quintessence models that best fit observational data can predict a value for the dark energy equation of state at present that is significantly different from the best-fit value of w 0 obtained assuming the parameterization above. In addition, the analysis reveals an approximate degeneracy of the w 0 –w a parameterization that explains the eccentricity and orientation of the likelihood contours presented in recent observational studies.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

A classical model for three-body interactions in aqueous ionic systems

We present a classical induction model to evaluate the three-body ion–water–water (I–W–W) and water–water–water (W–W–W) interactions in aqueous ionic systems. The classical description of the induction energy is based on electrostatic distributed multipoles up to hexadecapole and distributed polarizabilities up to quadrupole–quadrupole on the O and H atoms of water. The monatomic ions were described by a point charge and a dipole–dipole polarizability, while for the polyatomic ions, distributed multipoles up to hexadecapole and distributed polarizabilities up to quadrupole–quadrupole were used. The accuracy of the classical model is benchmarked against an accurate dataset of 936 (I–W–W) and 2184 (W–W–W) three-body terms for 13 different monatomic and polyatomic cation and anion systems. The classical model shows excellent agreement with the reference second order Moller–Plesset and coupled-cluster single double and perturbative triple [CCSD(T)] three-body energies. The Root-Mean-Square-Errors (RMSEs) for monatomic cations, monatomic anions, and polyatomic ions were 0.29, 0.25, and 0.12 kcal/mol, respectively. The corresponding RMSE for 1744 CCSD(T)/aVTZ three-body (W–W–W) energies, used to train MB-pol, was 0.12 kcal/mol. The accuracy of the proposed classical model demonstrates that the three-body term for aqueous ionic systems can be accurately modeled classically. This approach provides a fast, efficient, and as-accurate path toward modeling the three-body term in aqueous ionic systems that is fully transferable across systems with different ions without the need to fit to tens of thousands of ab initio calculations for each ion to extend existing many-body force fields to interactions between water and ions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

First use of an InSb crystal for x-ray imaging spectroscopy of highly ionized tungsten in the Wendelstein 7-X stellarator

Advances in time and space resolved measurements of highly charged states of tungsten (W) through x-ray imaging spectroscopy have enabled investigation of impurity transport in the Wendelstein 7-X (W7-X) stellarator. The high-resolution x-ray imaging spectrometer (HR-XIS) system on W7-X utilizes the Bragg diffraction properties of a set of multiple crystals to measure a range of impurity emission lines within sections of the 1–7 Å wavelength range, including transitions of W. A new indium–antimonide crystal has been installed on the HR-XIS system to allow viewing of the 5.5–6.2 Å region focusing on emissions of W. Consequently, many bright W emission lines from W 40+ to W 47+ were observed in this wavelength range, both in plasmas with injected W and in those with only intrinsic W impurity sources, showing the high sensitivity of the diagnostic. Three W 46+ emissions correspond in wavelength and intensity with calculated photon emissivity coefficients and can be exploited for W transport and concentration applications in plasmas with T e ≳ 2.1 keV. Here, an estimate of the core W density behavior in two separate turbulence-reduced ‘high-performance’ (HP) discharges on W7-X is done using the 5.6893 Å W 46+ line. The n W behavior in HP scenarios can be explained by previous experimental results and neoclassical predictions.

XICS↗
NASA NTRS1986

Characterization of simulated small-droplet fuel sprays

A two-fluid pneumatic atomizer operating at relatively high liquid and gas pressures produced water sprays that simulated small-droplet clouds of liquid fuel for use in studying vaporization and fuel-air mixing effects on combustor performance and emissions. To characterize the sprays, a scattered-light scanning instrument was developed and measurements of volume median or volume mean diameter, D sub V.5, were correlated with D sub O, W sub w, and W sub n, i.e., orifice diameter, water, and nitrogen gas flow rates, respectively, to give the general expression: D sub v.5 approx. (D sub o sup 0.2) (W sub w sup m) (W sub n sup n), which yields D sub v.5 = 45 (D sub o sup 0.2) (W sub w sup 0.2) (W sub w sup - 1.2). Values of D sub o, W sub w, and W sub n are in centimeters and grams/second, respectively. Farther downstream at an axial distance of 6.7 cm, exponent m increased from 0.2 to 0.4 and exponent n decreased from -1.2 to -1.0 and at a distance of 25 cm downstream of the atomizer, n decreased to -0.8. The increase in exponent m and decrease in exponent n was attributed to a loss of very small droplets from the spray due primarily to vaporization and diffusion effects on clouds of small droplets traveling a distance of 25 cm.

Ingebo, R. D.↗
NASA NTRS1986

Characterization of simulated small-droplet fuel sprays

A two-fluid pneumatic atomizer operating at relatively high liquid and gas pressures produced water sprays that simulated small-droplet clouds of liquid fuel for use in studying vaporization and fuel-air mixing effects on combustor performance and emissions. To characterize the sprays, a scattered-light scanning instrument was developed and measurements of volume median or volume mean diameter, D sub V.5, were correlated with D sub O, W sub w, and W sub n, i.e., orifice diameter, water, and nitrogen gas flow rates, respectively, to give the general expression: D sub v.5 approx. (D sub O sup 0.2) (W sub w sup m) (W sub n sup n), which yields D sub v.5 = 45 (D sub o sup 0.2) (W sub w sup 0.2) (W sub w sup -1.2). Values of D sub 0, W sub w, and W sub n are in centimeters and grams/second, respectively. Farther downstream at an axial distance of 6.7 cm, exponent m increased from 0.2 to 0.4 and exponent n decreased from -1.2 to -1.0 and at a distance of 25 cm downstream of the atomizer, n decreased to -0.8. The increase in exponent m and decrease in exponent n was attributed to a loss of very small droplets from the spray due primarily to vaporization and diffusion effects on clouds of small droplets traveling a distance of 25 cm.

Ingebo, R. D.↗
NASA NTRS2021

Distinct Surface Response to Black Carbon Aerosols

For the radiative impact of individual climate forcings, most previous studies focused on the global mean values at the top of the atmosphere (TOA), and less attention has been paid to surface processes, especially for black carbon (BC) aerosols. In this study, the surface radiative responses to five different forcing agents were analyzed by using idealized model simulations. Our analyses reveal that for greenhouse gases, solar irradiance, and scattering aerosols, the surface temperature changes are mainly dictated by the changes of surface radiative heating, but for BC, surface energy redistribution between different components plays a more crucial role. Globally, when a unit BC forcing is imposed at TOA, the net shortwave radiation at the surface decreases by −5.87±0.67 W m −2 (W m −2 ) −1 (averaged over global land without Antarctica), which is partially offset by increased downward longwave radiation (2.32±0.38 W m −2 (W m −2 ) −1 from the warmer atmosphere, causing a net decrease in the incoming downward surface radiation of −3.56±0.60 W m −2 (W m −2 ) −1 . Despite a reduction in the downward radiation energy, the surface air temperature still increases by 0.25±0.08 K because of less efficient energy dissipation, manifested by reduced surface sensible (−2.88±0.43 W m −2 (W m −2 ) −1 ) and latent heat flux (−1.54±0.27 W m −2 (W m −2 ) −1 ), as well as a decrease in Bowen ratio (−0.20±0.07 (W m −2 ) −1 ). Such reductions of turbulent fluxes can be largely explained by enhanced air stability (0.07±0.02 K (W m −2 ) −1 ), measured as the difference of the potential temperature between 925 hPa and surface, and reduced surface wind speed (−0.05±0.01 m s −1 (W m −2 ) −1 ). The enhanced stability is due to the faster atmospheric warming relative to the surface, whereas the reduced wind speed can be partially explained by enhanced stability and reduced Equator-to-pole atmospheric temperature gradient. These rapid adjustments under BC forcing occur in the lower atmosphere and propagate downward to influence the surface energy redistribution and thus surface temperature response, which is not observed under greenhouse gases or scattering aerosols. Our study provides new insights into the impact of absorbing aerosols on surface energy balance and surface temperature response.

radiative impact↗
DOE OSTI2020

Materials Data on W3Br8 by Materials Project

W3Br8 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent W+2.67+ sites. In the first W+2.67+ site, W+2.67+ is bonded to five Br1- atoms to form edge-sharing WBr5 square pyramids. There are a spread of W–Br bond distances ranging from 2.59–2.61 Å. In the second W+2.67+ site, W+2.67+ is bonded to five Br1- atoms to form edge-sharing WBr5 square pyramids. There are a spread of W–Br bond distances ranging from 2.54–2.68 Å. There are six inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a single-bond geometry to one W+2.67+ atom. In the second Br1- site, Br1- is bonded in a 8-coordinate geometry to three W+2.67+ and one Br1- atom. The Br–Br bond length is 3.86 Å. In the third Br1- site, Br1- is bonded in a 4-coordinate geometry to three W+2.67+ and one Br1- atom. The Br–Br bond length is 3.82 Å. In the fourth Br1- site, Br1- is bonded in a 1-coordinate geometry to three W+2.67+ and one Br1- atom. The Br–Br bond length is 3.98 Å. In the fifth Br1- site, Br1- is bonded in a 2-coordinate geometry to six Br1- atoms. There are one shorter (2.42 Å) and one longer (3.10 Å) Br–Br bond lengths. In the sixth Br1- site, Br1- is bonded in a single-bond geometry to one W+2.67+ and one Br1- atom.

36 MATERIALS SCIENCE↗