Topics

PubMed Journals Articles About "Supercompliant Soft Crystal With Ultralow Thermal Conductivity" RSS

16:06 EST 15th December 2019 | BioPortfolio

Supercompliant Soft Crystal With Ultralow Thermal Conductivity PubMed articles on BioPortfolio. Our PubMed references draw on over 21 million records from the medical literature. Here you can see the latest Supercompliant Soft Crystal With Ultralow Thermal Conductivity articles that have been published worldwide.

More Information about "Supercompliant Soft Crystal With Ultralow Thermal Conductivity" on BioPortfolio

We have published hundreds of Supercompliant Soft Crystal With Ultralow Thermal Conductivity news stories on BioPortfolio along with dozens of Supercompliant Soft Crystal With Ultralow Thermal Conductivity Clinical Trials and PubMed Articles about Supercompliant Soft Crystal With Ultralow Thermal Conductivity for you to read. In addition to the medical data, news and clinical trials, BioPortfolio also has a large collection of Supercompliant Soft Crystal With Ultralow Thermal Conductivity Companies in our database. You can also find out about relevant Supercompliant Soft Crystal With Ultralow Thermal Conductivity Drugs and Medications on this site too.

Showing "Supercompliant Soft Crystal with Ultralow Thermal Conductivity" PubMed Articles 1–25 of 6,000+

Supercompliant and Soft (CH_{3}NH_{3})_{3}Bi_{2}I_{9} Crystal with Ultralow Thermal Conductivity.

In this Letter, we show the phonon dispersion of (CH_{3}NH_{3})_{3}Bi_{2}I_{9} single crystals at 300 K measured by inelastic x-ray scattering. The frequencies of acoustic phonons are among the lowest of crystals. Nanoindentation measurements verified that these crystals are very compliant and considerably soft. The frequency overlap between acoustic and optical phonons results in strong acoustic-optical scattering. All these features lead to an ultralow thermal conductivity. The fundamental knowledge obta...


Ultralow lattice thermal conductivity induced high thermoelectric performance in the δ-CuS monolayer.

Motivated by the recent experimental exfoliation of β-Cu2S thin films and the theoretical finding of a new phase labeled the δ-Cu2S monolayer, we carried out extensive studies on thermal conductivity and thermoelectric properties of the new phase using first principles combined with Boltzmann transport theory, focusing on the analysis of group velocities, Gruneisen parameters, three-phonon scattering rates, and the scattering phase space. Our results show that the δ-Cu2S monolayer exhibits an intrinsical...

High Porosity in Nanostructured n-Type Bi2Te3 Obtaining Ultralow Lattice Thermal Conductivity.

Porous structure possesses full potentials to develop high-performance thermoelectric materials with low lattice thermal conductivity. In this study, n-type porous nanostructured Bi2Te3 pellet is fabricated by sintering Bi2Te3 nanoplates synthesized with a facile solvothermal method. With adequate sublimations of Bi2TeO5 during the spark plasma sintering, homogeneously distributed pores and dense grain boundaries are successfully introduced into the Bi2Te3 matrix, causing strong phonon scatterings. From whi...


Ultralow Thermal Conductivity in Chain Like TlSe due to Inherent Tl+ Rattling.

Understanding the mechanism that correlates phonon transport with chemical bonding and solid-state structure is the key to envisage and develop materials with ultralow thermal conductivity, which are essential for efficient thermoelectrics and thermal barrier coatings. We synthesised thallium selenide (TlSe), which comprised of intertwined stiff and weakly bonded substructures, exhibits intrinsically ultralow lattice thermal conductivity (κL) of 0.62 - 0.4 W/mK in the range 300 to 573 K. Ultralow κL of Tl...

Si and Ge allotrope heterostructured nanowires: experimental evaluation of the thermal conductivity reduction.

We have studied the thermal conductivity of Ge and Si allotrope heterostructured nanowires (NWs) synthesized by phase transformation. The NWs are composed of successive hexagonal 2H and cubic diamond 3C crystal phase along the <111> axis. Using 3ω-SThM (Scanning Thermal Microscopy) on NWs embedded in a silica matrix, we present the first experimental evidence of thermal conductivity reduction in such allotrope 2H/3C heterostructured NWs.
 In Ge heterostructured 2H/3C NWs, similarly to...

Hierarchical Cellular Structured Ceramic Nanofibrous Aerogels with Temperature-Invariant Superelasticity for Thermal Insulation.

Silica aerogels are attractive for thermal insulation due to their low thermal conductivity and good heat resistance performance. However, the fabrication of silica aerogels with temperature-invariant superelasticity and ultralow thermal conductivity has remained extremely challenging. Herein, we designed and synthesized a hierarchical cellular structured silica nanofibrous aerogel by using electrospun SiO2 nanofibers (SNFs) and SiO2 nanoparticle aerogels (SNAs) as the matrix and SiO2 sol as the high-temper...

Boosting thermoelectric performance of SnSe via tailoring of band structure, suppressing bipolar thermal conductivity and introducing large mass fluctuation.

Here, we report a peak ZT of 1.85 at 873 K for sulfur and Pb codoped polycrystalline SnSe by boosting electrical transport properties while suppressing lattice thermal conductivity. Compared to single sulfur doped samples, the carrier concentration is improved one order of magnitude by Pb incorporation, thereby contributing to improved electrical conductivity and power factor. Moreover, introducing of sulfur and Pb suppresses bipolar thermal conductivity by enlarging band gap. The lattice thermal conductivi...

Metal-Level Thermally Conductive yet Soft Graphene Thermal Interface Materials.

Along with the technology evolution for dense integration of high-power, high-frequency devices in electronics, the accompanying interfacial heat transfer problem leads to urgent demands for advanced thermal interface materials (TIMs) with both high through-plane thermal conductivity and good compressibility. Most metals have satisfactory thermal conductivity but relatively high compressive modulus, and soft silicones are typically thermal insulators (0.3 W m K). Currently, it is a great challenge to develo...

Tin Acceptor Doping Enhanced Thermoelectric Performance of n-Type Yb Single-Filled Skutterudites via Reduced Electronic Thermal Conductivity.

Although introducing more fillers in nanocages is beneficial to gain low lattice thermal conductivity within filling fraction limit, accompanying high electronic thermal conductivity usually results in an unsatisfactory figure of merit ZT in CoSb. In this work, Sn is adopted to tailor the electronic transport behavior for a high-filled YbCoSb alloy through rapid melt spinning combined with hot-press sintering processes. In spite of the reduced electrical conductivity, the power factors are scarcely influenc...

Disorder limits the coherent phonon transport in two-dimensional phononic crystal structures.

Recently, increasing efforts are being made to control thermal transport via coherent phonons in periodic phononic structures; however, the direct observation of coherent phonon transport is experimentally very difficult at ambient temperature, and the importance of coherent phonons to the total thermal conductivity has not been critically assessed to date. In this study, using the non-equilibrium molecular dynamics simulations, we studied coherent phonon transport in a C3N phononic crystal (CNPnC) structur...

Anomalous temperature dependent thermal conductivity of two dimensional silicon carbide.

Recently, two-dimensional silicon carbide (2D-SiC) has attracted considerable interest due to its exotic electronic and optical properties. Here, we explore the thermal properties of 2D-SiC using reverse non-equilibrium molecular dynamics simulation. At room temperature, a thermal conductivity of ~313 W/mK is obtained for 2D-SiC which is one order higher than that of silicene. Above room temperature, the thermal conductivity deviates the normal 1/T law and shows an anomalous slowly decreasing behavior. To e...

Highly Anisotropic Thermal Transport in LiCoO.

LiCoO2 is the prototypical cathode in lithium-ion batteries. Its crystal structure consists of Li+ and CoO2- layers that alternate along the hexagonal axis. It is well established that the ionic and electronic conduction are anisotropic, but little is known regarding the heat transport. We analyse the phonon dispersion and lifetimes using anharmonic lattice dynamics based on quantum-chemical force constants. Around room temperature, the thermal conductivity in the hexagonal ab plane of the layered cathode ...

Enhancement of Thermoelectric Properties in Pd-In Co-doped SnTe and Its Phase Transition Behavior.

SnTe have attracted more and more attention due to the similar band and crystal structure with high performance thermoelectric materials PbTe. Here, we introduced Pd into SnTe and the valence band convergence was confirmed by first principles calculation. In the experimental process, we found that Pd-doped SnTe exhibit a reduced thermal conductivity because of softening chemical bonds and grain refining effects. To further improve the thermoelectric performance, Pd-In co-doped SnTe samples were prepared and...

A robust model for estimating thermal conductivity of liquid alkyl halides.

Thermal conductivity is an essential thermodynamic property in chemical engineering application. As a result, estimating the thermal conductivity of organic compounds is of significance in industry production. Alkyl halides are important organic intermediates and raw materials, but little investigations have been performed to estimate their thermal conductivity. In this study, the structures of compounds were optimized in Gaussian 09W and molecular descriptors were extracted by Dragon software. Finally, we ...

Low thermal conductivity of peanut-shaped carbon nanotube and its insensitive response to uniaxial strain.

Motivated by the experimental synthesis of peanut-shaped carbon nanotubes (PSNTs) that combine the novel features of fullerene and carbon nanotube (CNT), we study the thermal conductivity of a PSNT (1dp08) and its response to different strains by using non-equilibrium molecular dynamics simulations and lattice dynamics together with density functional theory. We find that the thermal conductivity of the PSNT is reduced by more than 90% as compared to that of CNTs, and remains almost the same when different ...

Investigation of thermal properties of DNA structure with precise atomic arrangement via equilibrium and non-equilibrium molecular dynamics approaches.

Thermal conductivity of Deoxyribonucleic acid molecules is important for nanotechnology applications. Theoretical simulations based on simple models predict thermal conductivity for these molecular structures.

Rattling-Induced Ultra-low Thermal Conductivity Leading to Exceptional Thermoelectric Performance in AgInS.

Rattling has emerged as one of the most significant phenomenon for notably reducing the thermal conductivity in complex crystal systems. In this work using first-principles density functional theory, we found that rattlers can be hosted in simpler crystal system such as AgInS and CuInS. Rattlers Ag and Cu exhibit weak and anisotropic bonding with the neighbouring In and S and reside in a very shallow anharmonic potential wells. The phonon spectra of these compounds have multiple avoided crossing of optical ...

Crosslinking Effect on Thermal Conductivity of Electrospun Poly(acrylic acid) Nanofibers.

The thermal conductivity () of poly(acrylic acid) (PAA) nanofibers, which were electrospun at various electrospinning voltages, was measured using suspended microdevices. While the thermal conductivities of the as-spun PAA nanofibers varied depending on the electrospinning voltages, the most pronounced 3.1-fold increase in thermal conductivity in comparison to that of bulk PAA was observed at the electrospinning voltage of 14 kV. On the other hand, a reduction in the thermal conductivity of the nanofibers w...

Fast computation of soft tissue thermal response under deformation based on fast explicit dynamics finite element algorithm for surgical simulation.

During thermal heating surgical procedures such as electrosurgery, thermal ablative treatment and hyperthermia, soft tissue deformation due to surgical tool-tissue interaction and patient movement can affect the distribution of thermal energy induced. Soft tissue temperature must be obtained from the deformed tissue for precise delivery of thermal energy. However, the classical Pennes bio-heat transfer model can handle only the static non-moving state of tissue. In addition, in order to enable a surgeon to ...

High Thermal Boundary Conductance across Heterogeneous GaN-SiC Bonded Interfaces.

High-power GaN-based electronics are limited by high channel temperature induced by self-heating, which degrades device performance and reliability. Increasing the thermal boundary conductance (TBC) between GaN and SiC will aid in the heat dissipation of GaN-on-SiC devices by taking advantage of the high thermal conductivity of SiC substrates. For the typical growth method, there are issues concerning the transition layer at the interface and low-quality GaN adjacent the interface, which impedes heat flow. ...

Ion write micro-thermotics: programing thermal metamaterials at the microscale.

Considerable advances in manipulating heat flow in solids have been made through the innovation of artificial thermal structures such as thermal diodes, camouflages and cloaks. Such thermal devices can be readily constructed only at the macro-, centimeter- scale by mechanically assembling different materials with distinct values of thermal conductivity. Rapidly growing needs in areas such as thermal management of microelectronics require these concepts to be extended to and explored at the microscale. We de...

First-principles study of thermal transport properties in the two- and three-dimensional forms of BiOSe.

Recently, an air-stable layered semiconductor Bi2O2Se has been synthesized [Nat. Nanotechnol., 2017, 12, 530; Nano Lett. 2017, 17, 3021]. It possesses ultrahigh mobility, semiconductor properties, excellent environmental stability and easy accessibility. Here, we report on the thermal transport properties in monolayer (ML), bilayer (BL), and bulk forms of Bi2O2Se using density-functional theory and the Boltzmann transport approach. The results show that the ML exhibits better thermal transport properties th...

Ferroelectric domain walls in PbTiO are effective regulators of heat flow at room temperature.

Achieving efficient spatial modulation of phonon transmission is an essential step on the path to phononic circuits using "phonon currents." With their intrinsic and reconfigurable interfaces-domain walls (DWs)-ferroelectrics are alluring candidates to be harnessed as dynamic heat modulators. This paper reports the thermal conductivity of single-crystal PbTiO thin films over a wide variety of epitaxial-strain-engineered ferroelectric domain configurations. The phonon transport is proved to be strongly affec...

Phononic thermal transport properties of C3N nanotubes.

Reverse non-equilibrium molecular dynamics (RNEMD) is employed to study the phononic thermal transport properties of CN nanotubes. We study the effect of nanotube length and diameter on the thermal conductivity and investigate the phonon transport transition from ballistic to diffusive regime in CN nanotubes. It is found that the thermal conductivity of C3N nanotubes is significantly lower than those of carbon nanotubes across the entire ballistic diffusive range. In addition, significantly lower ballistic ...

Infrared lattice dynamics in negative thermal expansion material in single-crystal ScF3.

Simple cubic ``open" perovskite ScF stands out among trifluoride materials in its large, isotropic negative thermal expansion, but also its proximity of its zero-temperature state to a structural phase transition. Here we report a temperature- and frequency-dependent lattice dynamical study of Brillouin zone center lattice excitations of single crystals of ScF using infrared reflectivity measurements. In addition to quantifying the mode strengths and energies in single crystals of this interesting material,...


Quick Search