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Transmission electron microscopy study of Pb-depleted disks in PbTe-based alloys

Published online by Cambridge University Press:  23 February 2011

Hengzhi Wang
Affiliation:
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467
Qinyong Zhang
Affiliation:
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467
Bo Yu
Affiliation:
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467
Hui Wang
Affiliation:
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467
Weishu Liu
Affiliation:
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467
Gang Chen*
Affiliation:
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Zhifeng Ren*
Affiliation:
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467
*
a)Address all correspondence to these authors. e-mail: [email protected]
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Abstract

Even though the crystal structure of lead telluride (PbTe) has been extensively studied for many years, we discovered that the structure has a strong tendency to form Pb-depleted disks on {001} planes. These disks are around 2–5 nm in diameter and less than 0.5 nm in thickness, with a volume density of around 9 × 1017 cm−3, resulting in lattice strain fields (3–20 nm) on both sides of the disks along their normal directions. Moreover, such disks were also observed in Pb-rich Pb1.3Te, Pb-deficient PbTe1.3, and thallium (Tl)-doped Tl0.01Pb0.99Te and Tl0.02Pb0.98Te crystals. Because of the effects of diffraction contrast imaging by transmission electron microscopy and orientations of the crystals, these native lattice strain fields were incorrectly recognized as precipitates or nanoinclusions in PbTe-based materials. This discovery provides new insight into the formation mechanism of the precipitates or nanoinclusions in PbTe-based materials.

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Articles
Copyright
Copyright © Materials Research Society 2011

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References

REFERENCES

1.Greig, D.: Thermoelectricity and thermal conductivity in the lead sulfide group of semiconductors. Phys. Rev. 120, 358 (1960).CrossRefGoogle Scholar
2.Lyden, H.A.: Temperature dependence of the effective masses in PbTe. Phys. Rev. 135, A514 (1964).CrossRefGoogle Scholar
3.Snyder, G.J. and Toberer, E.S.: Complex thermoelectric materials. Nat. Mater. 7, 105 (2008).CrossRefGoogle ScholarPubMed
4.Kanatzidis, M.G.: Nanostructured thermoelectrics: The new paradigm? Chem. Mater. 22, 648 (2010).CrossRefGoogle Scholar
5.Hsu, K.F., Loo, S., Guo, F., Chen, W., Dyck, J.S., Uher, C., Hogan, T., Polychroniadis, E.K., and Kanatzidis, M.G.: Cubic AgPbmSbTe2+m: Bulk thermoelectric materials with high figure of merit. Science 303, 818 (2004).CrossRefGoogle ScholarPubMed
6.Poudeu, P.F.P., Angelo, J.D., Downey, A.D., Short, J.L., Hogan, T.P., and Kanatzidis, M.G.: High thermoelectric figure of merit and nanostructuring in bulk p-type Na1-xPbmSbyTem+2. Angew. Chem. Int. Ed. 45, 3835 (2006).CrossRefGoogle Scholar
7.Zhou, M., Li, J.-F., and Kita, T.: Nanostructured AgPbmSbTem+2 system bulk materials with enhanced thermoelectric performance. J. Am. Chem. Soc. 130, 4527 (2008).CrossRefGoogle ScholarPubMed
8.Muhlberg, M. and Hesse, D.: TEM precipitation studies in Te-rich as-grown PbTe single crystals. Phys. Status Solidi A Appl. Res. 76, 513 (1983).CrossRefGoogle Scholar
9.Scanlon, W.W.: Precipitation of Te and Pb in PbTe crystals. Phys. Rev. 126, 509 (1962).CrossRefGoogle Scholar
10.Wang, G.Y., Shi, T.S., and Zhang, S.Y.: Microdefects in Te-rich PbTe bulk crystal. Chin. Phys. Lett. 12, 469 (1995).CrossRefGoogle Scholar
11.Wang, H., Li, J.-F., and Kita, T.: Thermoelectric enhancement at low temperature in nonstoichiometric lead-telluride compounds. J. Phys. D Appl. Phys. 40, 6839 (2007).CrossRefGoogle Scholar
12.Bauer, G., Burkhard, H., Heinrich, H., and Lopez-Otero, A.: Impurity and vacancy states in PbTe. J. Appl. Phys. 47, 1721 (1976).CrossRefGoogle Scholar
13.Ke, X.Z., Chen, C.F., Yang, J.H., Wu, L.J., Zhou, J., Li, Q., Zhu, Y.M., and Kent, P.R.C.: Microstructure and a nucleation mechanism for nanoprecipitates in PbTe-AgSbTe2. Phys. Rev. Lett. 103, 145502 (2009).CrossRefGoogle Scholar
14.Dresselhaus, M.S., Chen, G., Tang, M.Y., Yang, R.G., Lee, H., Wang, D.Z., Ren, Z.F., Fleurial, J.-P., and Gogna, P.: New directions for low-dimensional thermoelectric materials. Adv. Mater. 19, 1043 (2007).CrossRefGoogle Scholar
15.Poudel, B., Hao, Q., Ma, Y., Lan, Y.C., Minnich, A., Yu, B., Yan, X., Wang, D.Z., Muto, A., Vashaee, D., Chen, X.Y., Liu, J.M., Dresselhaus, M.S., Chen, G., and Ren, Z.F.: High-thermoelectric performance of nanostructured bismuth antimony telluride bulk alloys. Science 320, 634 (2008).CrossRefGoogle ScholarPubMed
16.Wang, X.W., Lee, H., Lan, Y.C., Zhu, G.H., Joshi, G., Wang, D.Z., Yang, J., Muto, A.J., Tang, M.Y., Klatsky, J., Song, S., Dresselhaus, M.S., Chen, G., and Ren, Z.F.: Enhanced thermoelectric figure of merit in nanostructured n-type silicon germanium bulk alloy. Appl. Phys. Lett. 93, 193121 (2008).CrossRefGoogle Scholar
17.Williams, D.B. and Carter, C.B.: Transmission Electron Microscopy (Springer, New York, 1996), Vol. 3, p. 417.CrossRefGoogle Scholar
18.Gomez, M.P., Stevenson, D.A., and Huggins, R.A.: Self-diffusion of Pb and Te in lead telluride. J. Phys. Chem. Solids. 32, 335 (1971).CrossRefGoogle Scholar
19.George, T.D. and Wagner, J.B.: Tracer diffusion of lead in lead telluride. J. Appl. Phys. 42, 220 (1971).CrossRefGoogle Scholar
20.Pennycook, S.J.: Atomic-scale imaging of materials by Z-contrast scanning transmission electron microscopy. Anal. Chem. 64(4), 263 (1992).CrossRefGoogle Scholar
21.Heremans, J.P., Jovovic, V., Toberer, E.S., Saramat, A., Kurosaki, K., Charoenphakdee, A., Yamanaka, S., and Snyder, G.J.: Enhancement of thermoelectric efficiency in PbTe by distortion of the electronic density of states. Science. 321, 554 (2008).CrossRefGoogle ScholarPubMed
22.He, J.Q., Gueguen, A., Sootsman, J.R., Zheng, J.-C., Wu, L.J., Zhu, Y.M., Kanatzidis, M.G., and Dravid, V.P.: Role of self-organization, nanostructuring, and lattice strain on phonon transport in NaPb18-xSnxBiTe20 thermoelectric materials. J. Am. Chem. Soc. 131, 17828 (2009).CrossRefGoogle ScholarPubMed
23.Cook, B.A., Kramer, M.J., Harringa, J.L., Han, M.-K., Chung, D.Y., and Kanatzidis, M.G.: Analysis of nanostructuring in high figure-of-merit Ag1-xPbmSbTe2+m thermoelectric materials. Adv. Funct. Mater. 19, 1254 (2009).CrossRefGoogle Scholar