Low Thermal Conductivity of Rare-Earth Zirconate-Stannate Solid Solutions (Yb2 Zr2 O7 )1−x (Ln2 Sn2 O7 ) x (Ln = Nd, Sm)

2015 ◽  
Vol 99 (1) ◽  
pp. 293-299 ◽  
Author(s):  
Meng Zhao ◽  
Xiaorui Ren ◽  
Jun Yang ◽  
Wei Pan
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Solid Solutions ◽  
Low Thermal Conductivity

scholarly journals High-entropy (Nd0.2Sm0.2Eu0.2Y0.2Yb0.2)4Al2O9 with good high temperature stability, low thermal conductivity and anisotropic thermal expansivity

2020 ◽  
Author(s):  
Zifan Zhao ◽  
Huimin Xiang ◽  
Heng Chen ◽  
Fu-zhi Dai ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Rare Earth ◽  
High Temperature ◽  
Phase Stability ◽  
Temperature Phase ◽  
Low Thermal Conductivity ◽  
High Entropy ◽  
Anisotropic Thermal Expansion

Abstract The critical requirements for the environmental barrier coating (EBC) materials of silicon-based ceramic matrix composites (CMCs) including good tolerance to harsh environments, thermal expansion match with the interlayer mullite, good high-temperature phase stability and low thermal conductivity. Cuspidine-structured rare-earth aluminates RE4Al2O9 have been considered as candidates of EBCs for their superior mechanical and thermal properties, but the phase transition at high temperatures is a notable drawback of these materials. To suppress the phase transition and improve the phase stability, a novel cuspidine-structured rare-earth aluminate solid solution (Nd0.2Sm0.2Eu0.2Y0.2Yb0.2)4Al2O9 was designed and successfully synthesized inspired by entropy stabilization effect of high entropy ceramics. The as-synthesized (Nd0.2Sm0.2Eu0.2Y0.2Yb0.2)4Al2O9 exhibits close thermal expansion coefficient (6.96×10-6 /K at 300-1473 K) to that of mullite, good phase stability from 300 K to 1473 K, and low thermal conductivity (1.50 W·m-1·K-1 at room temperature). In addition, strong anisotropic thermal expansion has been observed compared to Y4Al2O9 and Yb4Al2O9. The mechanism for low thermal conductivity is attributed to the lattice distortion and mass difference of the constituent atoms while the anisotropic thermal expansion is due to the anisotropic chemical bonding enhanced by the large size rare earth cations.

Low-Thermal-Conductivity Rare-Earth Zirconates for Potential Thermal-Barrier-Coating Applications

2004 ◽  
Vol 85 (12) ◽  
pp. 3031-3035 ◽  
Author(s):  
Jie Wu ◽  
Xuezheng Wei ◽  
Nitin P. Padture ◽  
Paul G. Klemens ◽  
Maurice Gell ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Thermal Barrier Coating ◽  
Thermal Barrier ◽  
Low Thermal Conductivity ◽  
Barrier Coating

Partially-Filled Skutterudites: Optimizing the Thermoelectric Properties

2000 ◽  
Vol 626 ◽  
Author(s):  
G.S. Nolas ◽  
M. Kaeser ◽  
R.T. Littleton ◽  
T.M. Tritt ◽  
H. Sellinschegg ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Thermoelectric Properties ◽  
Alkaline Earth ◽  
Small Diameter ◽  
Large Mass ◽  
Rare Earth Ions ◽  
Low Thermal Conductivity ◽  
Filled Skutterudites ◽  
Trivalent Rare Earth

ABSTRACTThe skutterudite family of compounds continues to be of interest for thermoelectric applications due to the low thermal conductivity obtained when filling the voids with small diameter, large mass interstitials such as trivalent rare-earth ions. In the last few years there has been a substantial experimental and theoretical effort in attempting to understand the transport properties of these compounds in order to optimize their thermoelectric properties. One such approach involves partially-filling the voids in attempting to optimize the power factor while maintaining low thermal conductivity. In this report experimental research on skutterudites with the voids partially filled with heavy mass lanthanide and alkaline-earth ions is reported.

scholarly journals High-entropy (Nd0.2Sm0.2Eu0.2Y0.2Yb0.2)4Al2O9 with good high temperature stability, low thermal conductivity and anisotropic thermal expansivity

2020 ◽  
Author(s):  
Zifan Zhao ◽  
Huimin Xiang ◽  
Heng Chen ◽  
Fu-zhi Dai ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Rare Earth ◽  
High Temperature ◽  
Phase Stability ◽  
Temperature Phase ◽  
Low Thermal Conductivity ◽  
High Entropy ◽  
Anisotropic Thermal Expansion

Abstract The critical requirements for the environmental barrier coating (EBC) materials of silicon-based ceramic matrix composites (CMCs) including good tolerance to harsh environments, thermal expansion match with the interlayer mullite, good high-temperature phase stability and low thermal conductivity. Cuspidine-structured rare-earth aluminates RE4Al2O9 have been considered as candidates of EBCs for their superior mechanical and thermal properties, but the phase transition at high temperatures is a notable drawback of these materials. To suppress the phase transition and improve the phase stability, a novel cuspidine-structured rare-earth aluminate solid solution (Nd0.2Sm0.2Eu0.2Y0.2Yb0.2)4Al2O9 was designed and successfully synthesized inspired by entropy stabilization effect of high entropy ceramics. The as-synthesized (Nd0.2Sm0.2Eu0.2Y0.2Yb0.2)4Al2O9 exhibits close thermal expansion coefficient (6.96×10-6 /K at 300-1473 K) to that of mullite, good phase stability from 300 K to 1473 K, and low thermal conductivity (1.50 W·m-1·K-1 at room temperature). In addition, strong anisotropic thermal expansion has been observed compared to Y4Al2O9 and Yb4Al2O9. The mechanism for low thermal conductivity is attributed to the lattice distortion and mass difference of the constituent atoms while the anisotropic thermal expansion is due to the anisotropic chemical bonding enhanced by the large size rare earth cations.

Low-Thermal-Conductivity Rare-Earth Zirconates for Potential Thermal-Barrier-Coating Applications.

ChemInform ◽  
2003 ◽  
Vol 34 (10) ◽  
Author(s):  
Jie Wu ◽  
Xuezheng Wei ◽  
Nitin P. Padture ◽  
Paul G. Klemens ◽  
Maurice Gell ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Thermal Barrier Coating ◽  
Thermal Barrier ◽  
Low Thermal Conductivity ◽  
Barrier Coating

scholarly journals Charting Lattice Thermal Conductivity for Inorganic Crystals and Discovering Rare Earth Chalcogenides for Thermoelectrics

2021 ◽  
Author(s):  
Taishan Zhu ◽  
Ran He ◽  
Sheng Gong ◽  
Tian Xie ◽  
Prashun Gorai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Thermoelectric Materials ◽  
Lattice Thermal Conductivity ◽  
Energy Landscape ◽  
Promising Candidate ◽  
Low Thermal Conductivity ◽  
Inorganic Crystals ◽  
The Future

Thermoelectricity produced from usually negative-valued heat is a green and promising candidate on the future energy landscape. The most effective thermoelectric materials exhibit low thermal conductivity κ. However, less than...

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