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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,243 records · Page 69
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Tunable and reconfigurable atomically thin heterostructures

Heterocrystals of metal dichalcogenides and Bi 2 S 3 , Bi 2 Se 3 or Bi 2 Te 3 are presented, in which the metal dichalcogenides and Bi 2 S 3 , Bi 2 Se 3 or Bi 2 Te 3 do not largely retain their independent properties. These heterocrystals exhibit electronic and optical changes, which make them attractive for beyond-silicon electronics and optoelectronics. Particularly, these heterocrystals can be re-configured in a manner that allows bit writing and pattern drawing. Embodiments of these heterocrystals, methods of forming these heterocrystals, methods of reconfiguring the heterocrystals, information storage devices, optoelectronic circuits and photonic crystals are presented.

Vargas, Anthony↗
DOE OSTI2023

Tunable anisotropy of co-based nanocomposites for magnetic field sensing and inductor applications

A method includes producing an amorphous precursor to a nanocomposite, the amorphous precursor comprising a material that is substantially without crystals not exceeding 20% volume fraction; performing devitrification of the amorphous precursor, wherein the devitrification comprises a process of crystallization; forming, based on the devitrification, the nanocomposite with nano-crystals that contains an induced magnetic anisotropy; tuning, based on one or more of composition, temperature, configuration, and magnitude of stress applied during annealing and modification, the magnetic anisotropy of the nanocomposite; and adjusting, based on the tuned magnetic anisotropy, a magnetic permeability of the nanocomposite.

Leary, Alex M.↗
DOE OSTI2023

Tunable plasmonic color device and method of making the same

A plasmonic system is disclosed. The system includes at least one polarizer that is configured to provide at least one linearly polarized broadband light beam, an anisotropic plasmonic metasurface (APM) assembly having a plurality of nanoantennae each having a predetermined orientation with respect to a global axis representing encoded digital data, the APM assembly configured to receive the at least one linearly polarized broadband light beam and by applying localized surface plasmon resonance reflect light with selectable wavelengths associated with the predetermined orientations of the nanoantennae, and at least one analyzer that is configured to receive the reflected light with selectable wavelength, wherein the relative angles between each of the at least one analyzers and each of the at least one polarizers are selectable with respect to the global axis, thereby allowing decoding of the digital data.

Kildishev, Alexander V.↗
DOE OSTI2023

Crosslinked polymers with tunable coefficients of thermal expansion

Curatives and their resulting thermosets and other crosslinked polymers can reduce thermal expansion mismatch between an encapsulant and objects that are encapsulated. This can be accomplished by incorporating a negative CTE moiety into the thermoset resin or polymer backbone. The negative CTE moiety can be a thermal contractile unit that shrinks as a result of thermally induced conversion from a twist-boat to chair or cis/trans isomerization upon heating. Beyond CTE matching, other potential uses for these crosslinked polymers and thermosets include passive energy generation, energy absorption at high strain rates, mechanophores, actuators, and piezoelectric applications.

Redline, Erica Marie↗
DOE OSTI2023

Tunable nanotextured materials

A material with nanopillar structures extending from a substrate. The nanopillars are engageable by organisms to cause an interaction, such as cellular destruction.

Laible, Philip D.↗
DOE OSTI2023

Magnetic tunnel junctions with voltage tunable interlayer coupling for memory and sensor applications

Various examples are provided for magnetic tunnel junctions and applications thereof. In one example, a magnetic tunnel junction (MTJ) device includes a first ferromagnetic (FM) layer; a gadolinium oxide (GdOX) tunnel barrier disposed on the first ferromagnetic layer; and a second FM layer disposed on the GdOX tunnel barrier. In another example, a perpendicular MTJ (pMTJ) device includes a first layer including a magnetic material; a tunnel barrier disposed on the first layer to form the pMTJ; and a second layer including the magnetic material, the second layer disposed on the tunnel barrier.

Wang, Weigang↗
DOE OSTI2023

Tunable doping of carbon nanotubes through engineered atomic layer deposition

A carbon nanotube field effect transistor (CNFET), that has a channel formed of carbon nanotubes (CNTs), includes a layered deposit of a nonstoichiometric doping oxide (NDO), such as HfOX, where the concentration of the NDO varies through the thickness of the layer(s). An n-type metal-oxide semiconductor (NMOS) CNFET made in this manner can achieve similar ON-current, OFF-current, and/or threshold voltage magnitudes to a corresponding p-type metal-oxide semiconductor (PMOS) CNFET. Such an NMOS and PMOS can be used to achieve a symmetric complementary metal-oxide semiconductor (CMOS) CNFET design.

Source record↗
DOE OSTI2023

Tunable negative coefficient thermal expansion materials and composites

The present disclosure is directed to variable composition ceramics. Zr (2−x) Hf (x) WP 2 O 12 and Hf 2 WP 2 O 12 exhibit large negative thermal expansion that is linear over a large temperature range up to at least 900° C., These new ceramic material particles may be mixed with polymers to make a composite suitable for use in backsheets for photovoltaic modules or in other applications. The thermal expansion coefficient of the composite can be tailored to match that of the solar cell in order to reduce stress resulting from daily thermal cycling.

Gordon, Margaret Ellen↗
DOE OSTI2023

Highly tunable, inexpensive and easily fabricated magnetocaloric materials

A method is provided of making a magnetocaloric alloy composition comprising Ni, Co, Mn, and Ti, which preferably includes certain beneficial substitutional elements, by melting the composition and rapidly solidifying the melted composition at a cooling rate of at least 100 K/second (Kelvin/second) to improve a magnetocaloric property of the composition. The rapidly solidified composition can be heat treated to homogenize the composition and annealed to tune the magneto-structural transition for use in a regenerator.

Bez, Henrique Neves↗