A Primer On Phonon Glass Electric...

PGEC

Stefan Bringuier

Overview

ThermoelectricMaterials

Figure of merit

Thermalconductivity

Crystals

Glass

ThermoelectricApplications andPerformance

Phonon GlassElectric Crystal

Skutterudite

Summary

References

A Primer On Phonon Glass Electric Crystal

Stefan Bringuier

Department of Materials Science and Engineering, University of Arizona

[email protected]://u.arizona.edu/~stefanb

May 1, 2012

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Overview

The Presentation will proceed as follow:

Review of Thermoelectric Materials.

Thermal Conductivity

- Crystalline material- Glass

Thermoelectric Applications and Performance.

Phonon Glass Electron Crystal (PGEC).

Summary of this presentation.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Overview



Thermal Conductivity- Crystalline material- Glass




PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Overview



Thermal Conductivity

- Crystalline material- Glass




PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

BackgroundIn the early 1800’s German physicist, ThomasJohann Seebeck, observed that when twodissimilar materials are joined together and athermal gradient is imposed; a voltage difference isproduced.

The relationship between the two is given by:

α =∆V

∆TWhere α is referred to as the Seebeck coefficient

The Seebeck coefficient is an intrinsic materialproperty.

Material α (µVK

)Metal 1-10Semiconductor 102-103

Insulators High

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Background

In the early 1800’s German physicist, Thomas JohannSeebeck, observed that when two dissimilar materialsare joined together and a thermal gradient is imposed; avoltage difference is produced.

The relationship between the two is given by:

α =∆V

∆TWhere α is referred to as the Seebeck coefficient

The Seebeck coefficient is an intrinsic materialproperty.

Material α (µVK

)Metal 1-10Semiconductor 102-103

Insulators High

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Continued . . .It was later observed by J.C. Peltier, a Frenchphysicist, that the when in reverse (i.e. an appliedvoltage) heat is ejected at the material junction.

The heat absorbed at the lower junction:

Q̇ = ΠI

Where Π is referred to as the Peltier coefficient.This phenomena has between employed in what isknown as a Peltier cooler.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Continued . . .

It was later observed by J.C. Peltier, a French physicist,that the when in reverse (i.e. an applied voltage) heat isejected at the material junction.

The heat absorbed at the lower junction:

Q̇ = ΠI

Where Π is referred to as the Peltier coefficient.

This phenomena has between employed in what isknown as a Peltier cooler.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Continued . . .

∗∗adapted from www.peltier-info.com

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Figure of Merit

The figure of merit (i.e. benchmark) of a thermoelectricmaterial is given by:

Z =σα2

κ

Where σ and κ are the electrical conductivity and thermalconductivity.

It is often convenient to make this quantity dimensionless bymultiplying a average temperature.

T̄ =T2 + T1

2

So now the dimensionless figure of merit is:

ZT̄

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Thermal Conductivity of Crystalline Materials

The transport of heat in crystals (excluding metals)is primarily due to lattice waves; acoustic phonons.

Heat transport is primarily limited by the scattering ofacoustic phonons, which is dictated by the mean freepath.The mean free path is given by :

l = Vgτ

where Vg is the group velocity (i.e. direction of energypropagation) and τ is the relaxation time.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Thermal Conductivity of Crystalline Materials

The transport of heat in crystals (excluding metals) isprimarily due to lattice waves; acoustic phonons.

Heat transport is primarily limited by thescattering of acoustic phonons, which is dictatedby the mean free path.The mean free path is given by :

l = Vgτ

where Vg is the group velocity (i.e. direction ofenergy propagation) and τ is the relaxation time.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Thermal Conductivity of Glassy Materials

Like crystals phonons carry heat in glasses, but dueto the lack of long-range order, they are scatteredrapidly.

This gives rise to poor thermal conduction for areasonable temperature range. At high enoughtemperatures radiative process dominate.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References




Material κ ( wm·k )Silica Aerogels 10−2

Wood 10−1

Glasses 0.6 − 1.5Soda-lime Silicate Glass 1.7Al2O3 30.0 − 35.0SiC 84.0 − 93.0Copper 401

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References


Like crystals phonons carry heat in glasses, but due tothe lack of long-range order, they are scattered rapidly.


PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References




Material κ ( wm·k )Silica Aerogels 10−2

Wood 10−1

Glasses 0.6 − 1.5Soda-lime Silicate Glass 1.7Al2O3 30.0 − 35.0SiC 84.0 − 93.0Copper 401

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Thermoelectric Applications

Power GenerationUsed in Cassini and Voyager NASA missions, life spanof 14 years.

Waste Heat Recovery

Active Cooling and Warming

Localized Cooling

CPUsBiological specimens

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References


Power Generation

Used in Cassini and Voyager NASA missions, life spanof 14 years.

Waste Heat Recovery


Localized Cooling

CPUsBiological specimens

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References


Power Generation

Used in Cassini and Voyager NASA missions, life spanof 14 years.

Waste Heat Recovery


Localized CoolingCPUsBiological specimens

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Performance

For a value for ZT of 1 , σ = 0.8mΩ · cm andthermal conductivity of 1.25 wm·k .

Ideally, ZT greater than 2 which requires 0 ≤ κ ≤ 0.1.

†

†Snyder et al.1

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Performance

For a value for ZT of 1 , σ = 0.8mΩ · cm and thermalconductivity of 1.25 wm·k .

Ideally, ZT greater than 2 which requires0 ≤ κ ≤ 0.1.

†

†Snyder et al.1

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Phonon Glass Electric Crystal

The concept initially proposed by G.A. Slack2, is ifone could incorporate the electrical conductivity ofa single crystal and the poor thermal conductivityof a glass, a very high ZT value may be attained.

G.A. Slack suggested that inserting defects intocrystalline compounds, one could possible give rise toevents which reduce phonon propagation.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Phonon Glass Electric Crystal

The concept initially proposed by G.A. Slack2, is if onecould incorporate the electrical conductivity of a singlecrystal and the poor thermal conductivity of a glass, avery high ZT value may be attained.

G.A. Slack suggested that inserting defects intocrystalline compounds, one could possible give riseto events which reduce phonon propagation.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

SkutteruditeSkutterudite is the name of the mineral for which the

structure was identified.

The space group is Im3 and typical chemical formula MX3, ex.(Co,Ni,Fe)As3

They behave like semiconductors when doped with p-type andn-type atoms.

Due to the open structure, large rare-earth atoms can be placedwithin unit cell.

Table 1 Structural parameters of known binary skutterudites

Lattice Voidconstant Density y z radius

Compound (Å) (g cm−3) (Å) (Å) (Å)

CoP3 7.7073 4.41 0.348 0.145 1.763CoAS3 8.2055 6.82 0.344 0.151 1.825CoSb3 9.0385 7.64 0.335 0.160 1.892RhP3 7.9951 5.05 0.355 0.139 1.909RhAs3 8.4507 7.21 0.348 0.145 1.934RhSb3 9.2322 7.90 0.342 0.151 2.024IrP3 8.0151 7.36 0.354 0.139 1.906IrAs3 8.4673 9.12 0.347 0.145 1.931IrSb3 9.2503 9.35 0.340 0.153 2.040 ‡

‡Nolas et al. 3

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

SkutteruditeSkutterudite is the name of the mineral for which the structurewas identified.

The space group is Im3 and typical chemical formula MX3,ex. (Co,Ni,Fe)As3







‡Nolas et al. 3

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References



They behave like semiconductors when doped with p-typeand n-type atoms.






‡Nolas et al. 3

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References




Due to the open structure, large rare-earth atoms can beplaced within unit cell.





‡Nolas et al. 3

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Continued . . .

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Continued . . .

These rare-earth atoms are weakly bound and thus willundergo large local anharmonic vibrations,causing them to“rattle” independently from other atoms 4.

The mass fluctuation scattering reduces the lattice thermalconductivity to 58% of original value.

§

§Nolas et al.3

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Continued . . .

These rare-earth atoms are weakly bound and thus will undergolarge local anharmonic vibrations,causing them to “rattle”independently from other atoms 4.

The mass fluctuation scattering reduces the lattice thermalconductivity to 58% of original value.

§

§Nolas et al.3

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Continued . . .

PbTe

Bi2Te3

TAGS

Zn4Sb3 Ba8Ga16Ge30

Ag9TlTe5 La3–xTe4Yb14MnSb11

Temperature°C0 200 400 600 8000

1

2

3SiGe

κ l(W

m–1K–

1 )

CeFe3CoSb12

Hf0.75Zr0.25NiSn

¶

‖

¶Synder et al.1‖Rogl et al.5

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Recent Progress

LETTERSPUBLISHEDONLINE:11MARCH2012 | DOI:10.1038/NMAT3273

Copperionliquid-likethermoelectricsHuiliLiu1,2,XunShi1,3*,FangfangXu3,LinlinZhang3,WenqingZhang3,LidongChen1*,QiangLi4,CtiradUher5,TristanDay6andG.JeffreySnyder6

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Summary

we have surveyed the following topics:

Thermoelectric materials

Thermal conductivity of crystalline and glass materials.

Thermoelectric application and performance

Phonon Glass Electric Crystals

Thank you!

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Summary



Thermal conductivity of crystalline and glassmaterials.



Thank you!

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

Summary



Thermal conductivity of crystalline and glass materials.



Thank you!

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

References I

[1] G. J. Snyder and E. S. Toberer, “Complexthermoelectric materials,” Nature Materials, vol. 7,p. 105, Feb. 2008.

[2] G. A. Slack, “Design concepts for improvedthermoelectric materials,” MRS Online ProceedingsLibrary, vol. 478, p. null, 1997.

[3] G. S. Nolas, D. T. Morelli, and T. M. Tritt,“SKUTTERUDITES: a Phonon-Glass-Electron crystalapproach to advanced thermoelectric energy conversionapplications,” Annual Review of Materials Science,vol. 29, no. 1, pp. 89–116, 1999.

[4] B. C. Sales, D. Mandrus, B. C. Chakoumakos,V. Keppens, and J. R. Thompson, “Filled skutteruditeantimonides:electron crystals and phonon glasses,”Physical Review B, vol. 56, pp. 15081–15089, Dec.1997.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

References II

[5] G. Rogl, A. Grytsiv, N. Melnychenko-Koblyuk, E. Bauer,S. Laumann, and P. Rogl, “Compositional dependenceof the thermoelectric properties of (Sr x ba x yb 1 2 x) y co 4 sb 12 skutterudites,” Journal of Physics:Condensed Matter, vol. 23, p. 275601, July 2011.

[6] M. S. Dresselhaus, G. Chen, M. Y. Tang, R. G. Yang,H. Lee, D. Z. Wang, Z. F. Ren, J. . Fleurial, andP. Gogna, “New directions for LowDimensionalthermoelectric materials,” Advanced Materials, vol. 19,pp. 1043–1053, Apr. 2007.

[7] J. Nyln, M. Andersson, S. Lidin, and U. Hussermann,“The structure of -Zn4Sb3: ordering of thePhonon-Glass thermoelectric material -Zn4Sb3,” J. Am.Chem. Soc., vol. 126, no. 50, pp. 16306–16307, 2004.

PGEC

Stefan Bringuier

Overview


Figure of merit

Thermalconductivity

Crystals

Glass



Skutterudite

Summary

References

References III[8] G. S. Nolas, M. Kaeser, R. T. Littleton, and T. M.

Tritt, “High figure of merit in partially filled ytterbiumskutterudite materials,” Applied Physics Letters,vol. 77, pp. 1855–1857, Sept. 2000.

[9] K. Takahata, Y. Iguchi, D. Tanaka, T. Itoh, andI. Terasaki, “Low thermal conductivity of the layeredoxide (Na,Ca)Co 2O 4: another example of a phononglass and an electron crystal,” Physical Review B,vol. 61, pp. 12551–12555, May 2000.

[10] T. M. Tritt, “Thermoelectric phenomena, materials,and applications,” Annual Review of MaterialsResearch, vol. 41, no. 1, pp. 433–448, 2011.

[11] G. J. Snyder, M. Christensen, E. Nishibori, T. Caillat,and B. B. Iversen, “Disordered zinc in Zn4Sb3 withphonon-glass and electron-crystal thermoelectricproperties,” Nature Materials, vol. 3, p. 458, June 2004.

[12] C. Kittel, Introduction to solid state physics. 1997.

OverviewThermoelectric MaterialsFigure of merit

Thermal conductivityCrystalsGlass

Thermoelectric Applications and PerformancePhonon Glass Electric CrystalSkutterudite

Summary

0.0: 0.1: 0.2: 0.3: 0.4: 0.5: anm0:

A Primer On Phonon Glass Electric...

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