Thermal conductivity of (Er1-xYx)(2)Ti2O7 pyrochlore oxide solid solutions
View/ Open
Date
2012-08Author
Bryan, Craig
Whitman, Catherine A.
Johnson, Michel B.
Niven, John F.
Murray, Patrick
Bourque, Alex
Dabkowska, Hanna A.
Gaulin, Bruce D.
White, Mary Anne
Metadata
Show full item recordAbstract
The thermal conductivities of pyrochlore oxide solid solutions of general formula
(Er1-xYx)(2)Ti2O7 with 0 <= x <= 1 have been determined for high-quality single crystals
aligned along the [110] direction, over the temperature range from 3 to 300 K. Er2Ti2O7 and Y2Ti2O7
are isostructural and Er3+ and Y3+ are within 1% in size, but differ by a factor of about 2 in mass.
Therefore, this system allows a clear test of the influence of mass of dopant on thermal
conductivity, while controlling for other factors such as dopant size and sample purity. Although
Y2Ti2O7 has a higher thermal conductivity than Er2Ti2O7 at T = 300 K, from 3 to 200 K their relative
thermal conductivities reverse. Furthermore, we observe significant decrease in thermal conductivity
upon doping Er2Ti2O7 with Y3+ ions, showing definitively that, in the temperature range from about 3
to 300 K, the impurity scattering effect of the lighter Y3+ ions is the predominant limiter of the
thermal conductivity. This conclusion is supported by the finding that the phonon mean free path of
the doped compounds decreases with increased dopant concentrations, increasing again as pure Y2Ti2O7
is approached.
Citation
Bryan, Craig, Catherine A. Whitman, Michel B. Johnson, John F. Niven, et al. 2012. "Thermal conductivity of (Er1-xYx)(2)Ti2O7 pyrochlore oxide solid solutions." Physical Review B 86(5): 054303-054303. Copyright © 2012 American Physical Society.