Enhanced thermoelectric power factor in Yb1-xSc xAl2 alloys using chemical pressure tuning of the Yb valence

Gloria J. Lehr, Donald T. Morelli, Hyungyu Jin, Joseph P. Heremans

Research output: Contribution to journalArticle

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Abstract

We have investigated the influence of Sc substitution on the transport and magnetic properties of YbAl2, a well-known intermediate valence compound. Sc substitution provides a chemical pressure that decreases the lattice constant and thereby alters the Yb valence as a function of composition and temperature. We observe a strong correlation between the Seebeck coefficient and the ratio of trivalent to divalent Yb in these compounds, as determined from magnetic susceptibility measurements. This correlation indicates that the largest absolute value of the Seebeck coefficient is achieved when the average Yb valence is near 2.5 (the ratio of divalent to trivalent Yb is 1:1). It is shown that Sc concentration can be used as a means to tune both the magnitude of the maximum of the Seebeck coefficient and the temperature at which this absolute maximum occurs, improving the prospects of the use of these materials in cryogenic Peltier coolers.

LanguageEnglish (US)
Article number223712
JournalJournal of Applied Physics
Volume114
Issue number22
DOIs
StatePublished - Dec 14 2013

Profile

Seebeck effect
tuning
valence
substitutes
coolers
cryogenics
transport properties
magnetic properties
magnetic permeability
temperature

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Enhanced thermoelectric power factor in Yb1-xSc xAl2 alloys using chemical pressure tuning of the Yb valence. / Lehr, Gloria J.; Morelli, Donald T.; Jin, Hyungyu; Heremans, Joseph P.

In: Journal of Applied Physics, Vol. 114, No. 22, 223712, 14.12.2013.

Research output: Contribution to journalArticle

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