scholarly journals Low thermal conductivity in a modular inorganic material with bonding anisotropy and mismatch

Science ◽  
2021 ◽  
pp. eabh1619
Author(s):  
Quinn D. Gibson ◽  
Tianqi Zhao ◽  
Luke M. Daniels ◽  
Helen C. Walker ◽  
Ramzy Daou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Inorganic Material ◽  
Phonon Dispersion ◽  
Spatial Arrangement ◽  
Vibrational Modes ◽  
Crystalline Materials ◽  
Low Thermal Conductivity ◽  
Transverse Modes ◽  
Different Types

The thermal conductivity of crystalline materials cannot be arbitrarily low as the intrinsic limit depends on the phonon dispersion. We used complementary strategies to suppress the contribution of the longitudinal and transverse phonons to heat transport in layered materials containing different types of intrinsic chemical interface. BiOCl and Bi2O2Se encapsulate these design principles for longitudinal and transverse modes respectively, and the bulk superlattice material Bi4O4SeCl2 combines these effects by ordering both interface types within its unit cell to reach an extremely low thermal conductivity of 0.1 W K−1 m−1 at room temperature along its stacking direction. This value comes within a factor of four of air. We demonstrated that chemical control of the spatial arrangement of distinct interfaces can synergically modify vibrational modes to minimize thermal conductivity.

scholarly journals Phonon hydrodynamics and ultrahigh–room-temperature thermal conductivity in thin graphite

Science ◽  
2020 ◽  
Vol 367 (6475) ◽  
pp. 309-312 ◽  
Author(s):  
Yo Machida ◽  
Nayuta Matsumoto ◽  
Takayuki Isono ◽  
Kamran Behnia
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Phonon Dispersion ◽  
High Conductivity ◽  
Temperature Range ◽  
A Value ◽  
Out Of Plane ◽  
Intimate Link

Allotropes of carbon, such as diamond and graphene, are among the best conductors of heat. We monitored the evolution of thermal conductivity in thin graphite as a function of temperature and thickness and found an intimate link between high conductivity, thickness, and phonon hydrodynamics. The room-temperature in-plane thermal conductivity of 8.5-micrometer-thick graphite was 4300 watts per meter-kelvin—a value well above that for diamond and slightly larger than in isotopically purified graphene. Warming enhances thermal diffusivity across a wide temperature range, supporting partially hydrodynamic phonon flow. The enhancement of thermal conductivity that we observed with decreasing thickness points to a correlation between the out-of-plane momentum of phonons and the fraction of momentum-relaxing collisions. We argue that this is due to the extreme phonon dispersion anisotropy in graphite.

Where Should We Look For High Zt Materials: Suggestions From Theory.

2000 ◽  
Vol 626 ◽  
Author(s):  
M. Fornari ◽  
D. J. Singh ◽  
I. I. Mazin ◽  
J. L. Feldman
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
First Principles ◽  
Room Temperature ◽  
First Principles Calculations ◽  
High Electrical Conductivity ◽  
Bulk Materials ◽  
Low Thermal Conductivity ◽  
Computational Exploration ◽  
Single Material

ABSTRACTThe key challenges in discovering new high ZT thermoelectrics are understanding how the nearly contradictory requirements of high electrical conductivity, high thermopower and low thermal conductivity can be achieved in a single material and based on this identifying suitable compounds. First principles calculations provide a material specific microscopic window into the relevant properties and their origins. We illustrate the utility of the approach by presenting specific examples of compounds belonging to the class of skutterudites that are or are not good thermoelectrics along with the microscopic reasons. Based on our computational exploration we make a suggestion for achieving higher values of ZT at room temperature in bulk materials, namely n-type La(Ru,Rh)4Sb12 with high La-filling.

Conductivity studies of Ni and Gd substituted BiCoO3

2014 ◽  
Vol 28 (05) ◽  
pp. 1450034 ◽  
Author(s):  
T. Ramachandran ◽  
N. E. Rajeevan ◽  
P. P. Pradyumnan
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Structural Studies ◽  
Reaction Route ◽  
Low Thermal Conductivity ◽  
Sem Micrograph ◽  
New Material ◽  
Cubic Structure ◽  
Solid State Reaction Route ◽  
Room Temperature Raman Spectrum

In this paper, we report the synthesis, thermal and electrical property studies of Ni 0.5 Gd 0.2 Bi 0.3 CoO 3, a new material for thermoelectric applications. The material was synthesized by solid state reaction route taking BiCoO 3 as basic matrix by substituting bismuth with nickel and gadolinium. Structural studies using room temperature XRD and room temperature Raman spectrum established cubic structure for Ni 0.5 Bi 0.5 CoO 3 and tetragonal structure for Ni 0.5 Gd 0.2 Bi 0.3 CoO 3. The SEM micrograph of the samples revealed crystallites of micrometer dimension with varying grain size. The sample showed interestingly low thermal conductivity and VRH mechanism was found to dominate in the electrical conduction at low temperature regime. The low thermal conductivity and moderate electrical conductivity is suggestive of strong candidature of the material for thermoelectric applications.

Elephant ivory: A low thermal conductivity, high strength nanocomposite

2006 ◽  
Vol 21 (1) ◽  
pp. 287-292 ◽  
Author(s):  
Michael B. Jakubinek ◽  
Champika J. Samarasekera ◽  
Mary Anne White
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
High Strength ◽  
Mean Free Path ◽  
Boundary Scattering ◽  
Low Thermal Conductivity ◽  
Recent Interest ◽  
Elephant Ivory ◽  
Nanocomposite Structures ◽  
Structure Properties

There has been much recent interest in heat transport in nanostructures, and alsoin the structure, properties, and growth of biological materials. Here we present measurements of thermal properties of a nanostructured biomineral, ivory. The room-temperature thermal conductivity of ivory is anomalously low in comparison with its constituent components. Low-temperature (2–300 K) measurements ofthermal conductivity and heat capacity reveal a glass-like temperature dependenceof the thermal conductivity and phonon mean free path, consistent with increased phonon-boundary scattering associated with nanostructure. These results suggest that biomineral-like nanocomposite structures could be useful in the design of novel high-strength materials for low thermal conductivity applications.

scholarly journals Unusually low thermal conductivity of atomically thin 2D tellurium

Nanoscale ◽  
2018 ◽  
Vol 10 (27) ◽  
pp. 12997-13003 ◽  
Author(s):  
Zhibin Gao ◽  
Fang Tao ◽  
Jie Ren
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Low Thermal Conductivity

We firstly find that tellurene has a compellingly low room temperature κL of 2.16 and 4.08 W m−1 K−1 along the armchair and zigzag directions.

Effect of Phonon Dispersion on Transport Properties of Single-Crystalline Dielectrics

2004 ◽  
Author(s):  
Mehdi Asheghi ◽  
Wenjun Liu ◽  
K. E. Goodson
Keyword(s):  
Thermal Conductivity ◽  
Phonon Dispersion ◽  
Additional Insight ◽  
Transverse Modes ◽  
Scattering Rate ◽  
Magnitude Variation ◽  
Silicon And Germanium ◽  
Conductivity Modeling ◽  
Insight Into ◽  
Mass Fluctuation

Thermal conductivity modeling using the Debye approximation can significantly reduce the complexity involved in the evaluation of thermal conductivity integral. Nevertheless, there are several compelling reasons (e.g., inconsistency between the estimations of the density of states used for heat capacity and thermal conductivity) that motivate more detailed modeling of the phonon dispersion in silicon or other diamond-like dielectrics. This manuscript presents closed-form expressions for the dispersion of the longitudinal and transverse modes in diamond-like dielectrics, which are then used to estimate the isotopic scattering rate, phonon spectrum and specific heat. The combinations of the above parameters are then used to predict the thermal conductivity of the bulk silicon and germanium with orders of magnitude variation in the mass fluctuation of isotopes and for the temperature range 2 to 1000 K. While this approach offers an elegant and consistent account of the phonon dispersion in diamond-like materials, however, provides no additional insight into the relative contributions of the longitudinal and transverse phonons to the heat transport.

Thermoelectric properties of the Al-TM-Si (TM = Mn, Re) 1/1-cubic approximant

2003 ◽  
Vol 805 ◽  
Author(s):  
Tsunehiro Takeuchi ◽  
Toshio Otagiri ◽  
Hiroki Sakagami ◽  
Uichiro Mizutani
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Thermoelectric Power ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Low Thermal Conductivity ◽  
Dimensionless Figure Of Merit

ABSTRACTThe electrical resistivity, thermoelectric power, and thermal conductivity were investigated for the Al71.6-xMn 17.4Six and Al71.6-xRe 17.4Six (7 ≤ x ≤ 12) 1/1-cubic approximants. A large thermoelectric power ranging from -40 to 90 μV/K and a low thermal conductivity less than 3 W/K·cm were observed at room temperatures. The electrical resistivity at room temperature for these approximants was kept below 4,000 μΩcm, that is much smaller than that in the corresponding quasicrystals. As a result of the large thermoelectric power, the low thermal conductivity, and the low electrical resistivity, large dimensionless figure of merit ZT = 0.10 (n-type) and 0.07 (p-type) were achieved for the Al71.6Re17.4Si11 and Al71.6Mn17.4Si11 at room temperature, respectively.

Extremely Low Thermal Conductivity Substances as Novel Thermoelectric Materials

2005 ◽  
Vol 886 ◽  
Author(s):  
Shinsuke Yamanaka ◽  
Ken Kurosaki ◽  
Atsuko Kosuga ◽  
Keita Goto ◽  
Hiroaki Muta
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Room Temperature ◽  
State Of The Art ◽  
Thermoelectric Figure ◽  
Low Thermal Conductivity ◽  
Thallium Compounds ◽  
Thallium Tellurides

ABSTRACTWe have prepared polycrystalline bulk samples of various thallium compounds and measured their thermoelectric properties. The most remarkable point of the thermoelectric properties of the thallium compounds is the extremely low thermal conductivity. The state-of-the-art thermoelectric materials such as Bi2Te3 and TAGS materials indicate relatively low the thermal conductivity, around 1.5 W/m/K. However, the thermal conductivity of the thallium compounds is below 0.5 W/m/K; especially that of silver thallium tellurides is around 0.25 W/m/K at room temperature. This extremely low thermal conductivity leads a great advantage for an enhancement of the thermoelectric performance. In this paper, we report on the properties of some thallium compounds selected for study as novel thermoelectric materials. One of these compounds seems to have a thermoelectric figure of merit comparable to those of state-of-the-art materials.

Thermoelectric Properties of Tl2Te-Sb2Te3 Pseudo-Binary System

2005 ◽  
Vol 886 ◽  
Author(s):  
Ken Kurisaki ◽  
Keita Goto ◽  
Atsuko Kosuga ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Binary System ◽  
Thermoelectric Properties ◽  
Room Temperature ◽  
State Of The Art ◽  
Electrical Performance ◽  
Low Thermal Conductivity ◽  
Maximum Value ◽  
P Type ◽  
Type Conduction

ABSTRACTPolycrystalline-sintered samples of thallium based substances, (Tl2Te)100−x(Sb2Te3)x (x= 0, 1, 5, 10), were prepared by melting Tl2Te and Sb2Te3 ingots followed by annealing in sealed quartz ampoules. The thermoelectric properties were measured from room temperature to around 600 K. The values of the Seebeck coefficient of all samples are positive, indicating a p-type conduction characteristic. The maximum value of the power factor is 6.53×10−4 Wm−1K−2 at 591 K obtained for x= 10 (Tl9SbTe6), which is about one order lower than those of state-of-the-art thermoelectric materials. All samples indicate an extremely low thermal conductivity, for example that of Tl2Te is approximately 0.35 Wm−1K−1 from room temperature to around 600 K. Although the electrical performance of the samples is not so good, the ZT value is relatively high due to the extremely low thermal conductivity. The maximum ZT value is 0.42 at 591 K obtained for Tl9SbTe6.

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