Effect of chemical pressure manipulation on the valence and thermoelectric properties of the intermediate valence compound YbCu2-xNixGe2

Gloria J. Lehr, Spencer L. Waldrop, Winston D. Carr, Donald T. Morelli

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The thermoelectric properties of YbCu2Ge2 at low temperature are unremarkable, however it has been found to be an intermediate valence compound. Previous work has shown that manipulation of valence in such compounds by chemical pressure can have dramatic effects on the value of the Seebeck coefficient. YbCu2Ge2 has been found to exist in a nearly divalent, Yb2+, state at room temperature, which if increased towards 2.5 has the promise of increasing the Seebeck coefficient substantially. In this study a full solid solution of YbCu2Ge2 and YbNi2Ge2 was created to exert a chemical pressure on the Yb and shift the valence away from the nominally divalent. A dramatic increase in the Seebeck coefficient was found as well as a substantial decrease in the thermal conductivity. These effects resulted in a substantial increase in ZT at low temperature and further emphasized the applicability and large effect that valence manipulation can have on intermediate valence compounds.

LanguageEnglish (US)
Title of host publicationTri-Technology Device Refrigeration (TTDR)
PublisherSPIE
Volume9821
ISBN (Electronic)9781510600621
DOIs
StatePublished - 2016
EventTri-Technology Device Refrigeration (TTDR) - Baltimore, United States
Duration: Apr 19 2016Apr 20 2016

Other

OtherTri-Technology Device Refrigeration (TTDR)
CountryUnited States
CityBaltimore
Period4/19/164/20/16

Profile

Seebeck coefficient
Manipulation
manipulators
valence
Seebeck effect
Coefficient
Thermal Conductivity
Temperature
Solid solutions
Thermal conductivity
Decrease
solid solutions
thermal conductivity
shift
room temperature

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics

Cite this

Lehr, G. J., Waldrop, S. L., Carr, W. D., & Morelli, D. T. (2016). Effect of chemical pressure manipulation on the valence and thermoelectric properties of the intermediate valence compound YbCu2-xNixGe2 In Tri-Technology Device Refrigeration (TTDR) (Vol. 9821). [98210H] SPIE. DOI: 10.1117/12.2228757

Effect of chemical pressure manipulation on the valence and thermoelectric properties of the intermediate valence compound YbCu2-xNixGe2 . / Lehr, Gloria J.; Waldrop, Spencer L.; Carr, Winston D.; Morelli, Donald T.

Tri-Technology Device Refrigeration (TTDR). Vol. 9821 SPIE, 2016. 98210H.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Lehr, GJ, Waldrop, SL, Carr, WD & Morelli, DT 2016, Effect of chemical pressure manipulation on the valence and thermoelectric properties of the intermediate valence compound YbCu2-xNixGe2 in Tri-Technology Device Refrigeration (TTDR). vol. 9821, 98210H, SPIE, Tri-Technology Device Refrigeration (TTDR), Baltimore, United States, 4/19/16. DOI: 10.1117/12.2228757
Lehr GJ, Waldrop SL, Carr WD, Morelli DT. Effect of chemical pressure manipulation on the valence and thermoelectric properties of the intermediate valence compound YbCu2-xNixGe2 In Tri-Technology Device Refrigeration (TTDR). Vol. 9821. SPIE. 2016. 98210H. Available from, DOI: 10.1117/12.2228757
Lehr, Gloria J. ; Waldrop, Spencer L. ; Carr, Winston D. ; Morelli, Donald T./ Effect of chemical pressure manipulation on the valence and thermoelectric properties of the intermediate valence compound YbCu2-xNixGe2 Tri-Technology Device Refrigeration (TTDR). Vol. 9821 SPIE, 2016.
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