while SrTiO3 exhibits promising electronic transport properties, its high thermal conductivity (κ) is detrimental for its use as a thermoelectric material. Here, we investigate the influence of oxygen non-stoichiometry on κ in bulk SrTiO3 ceramics. A significant reduction in κ was achieved in oxygen deficient SrTiO3−δ, owing to the presence of oxygen vacancies that act as phonon scattering centers. Upon oxidation of SrTiO3−δ, the κ of pristine SrTiO3 was recovered, suggesting that oxygen vacancies were indeed responsible for the reduction in κ. Raman spectroscopy was used as an independent tool to confirm the reduction of oxygen vacancies in SrTiO3−δ upon oxidation.
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J.F. Schooley, W.R. Hosler, and M.L. Cohen: Superconductivity in semiconducting SrTiO3. Phys. Rev. Lett. 12, 474 (1964).
C. Mitra, C. Lin, J. Robertson, and A.A. Demkov: Electronic structure of oxygen vacancies in SrTiO3 and LaAlO3. Phys. Rev. B 86, 155105 (2012).
D. Kan, T. Terashima, R. Kanda, A. Masuno, K. Tanaka, S. Chu, H. Kan, A. Ishizumi, Y. Kanemitsu, Y. Shimakawa, and M. Takano: Blue-light emission at room temperature from Ar+-irradiated SrTiO3. Nat. Mater. 4, 816 (2005).
K. Szot, W. Speier, G. Bihlmayer, and R. Waser: Switching the electrical resistance of individual dislocations in single-crystalline SrTiO3. Nat. Mater. 5, 312 (2006).
M. Janousch, G.I. Meijer, U. Staub, B. Delley, S.E. Karg, and B.P. Andreasson: Role of oxygen vacancies in Cr-doped SrTiO3 for resistance-change memory. Adv. Mater. 19, 2232 (2007).
W.D. Rice, P. Ambwani, J.D. Thompson, C. Leighton, and S.A. Crooker: Revealing optically induced magnetization in SrTiO3 using optically coupled SQUID magnetometry and magnetic circular dichroism. J. Vac. Sci. Technol. B, Nanotechnol. Microelectron. Mater. Process. Meas. Phenom. 32, 04E102 (2014).
I. Yoshida: Thermal conduction in ferroelectric ceramics. J. Phys. Soc. Jpn. 15, 2211 (1960).
Y. Suemune: Thermal conductivity of BaTiO3 and SrTiO3 from 4.5 to 300 K. J. Phys. Soc. Jpn. 20, 174 (1965).
E.F. Steigmeier: Field effect on the Cochran modes in SrTiO3 and KTaO3. Phys. Rev. 168, 523 (1968).
Y. Wang, K. Fujinami, R. Zhang, C. Wan, N. Wang, Y. Ba, and K. Koumoto: Interfacial thermal resistance and thermal conductivity in nanograined SrTiO3. Appl. Phys. Express 3, 031101 (2010).
E. Breckenfeld, R. Wilson, J. Karthik, A.R. Damodaran, D.G. Cahill, and L.W. Martin: Effect of growth induced (non)stoichiometry on the structure, dielectric response, and thermal conductivity of SrTiO3 thin films. Chem. Mater. 24, 331 (2012).
B.M. Foley, H.J. Brown-Shaklee, J.C. Duda, R. Cheaito, B.J. Gibbons, D. Medlin, J.F. Ihlefeld, and P.E. Hopkins: Thermal conductivity of nano-grained SrTiO3 thin films. Appl. Phys. Lett. 101, 231908 (2012).
D.-W. Oh, J. Ravichandran, C.-W. Liang, W. Siemons, B. Jalan, C.M. Brooks, M. Huijben, D.G. Schlom, S. Stemmer, L.W. Martin, A. Majumdar, R. Ramesh, and D.G. Cahill: Thermal conductivity as a metric for the crystalline quality of SrTiO3 epitaxial layers. Appl. Phys. Lett. 98, 221904 (2011).
S.R. Popuri, A.J.M. Scott, R.A. Downie, M.A. Hall, E. Suard, R. Decourt, M. Pollet, and J.W.G. Bos: Glass-like thermal conductivity in SrTiO3 thermoelectrics induced by A-site vacancies. RSC Adv. 4, 33720 (2014).
B. Zhang, J. Wang, T. Zou, S. Zhang, X. Yaer, N. Ding, C. Liu, L. Miao, Y. Li, and Y. Wu: High thermoelectric performance of Nb-doped SrTiO3 bulk materials with different doping levels. J. Mater. Chem. C 3, 11406 (2015).
D. Srivastava, C. Norman, F. Azough, M.C. Schäfer, E. Guilmeau, and R. Freer: Improving the thermoelectric properties of SrTiO3-based ceramics with metallic inclusions. J. Alloys Compd. 731, 723 (2018).
S. Bhattacharya, A. Mehdizadeh Dehkordi, S. Tennakoon, R. Adebisi, J.R. Gladden, T. Darroudi, H.N. Alshareef, and T.M. Tritt: Role of phonon scattering by elastic strain field in thermoelectric Sr1−xYxTiO3−δ. J. Appl. Phys. 115, 223712 (2014).
S. Bhattacharya, A.M. Dehkordi, H.N. Alshareef, and T.M. Tritt: Synthesis-property relationship in thermoelectric Sr1−xYbxTiO3−δ ceramics. J. Phys. D: Appl. Phys. 47, 385302 (2014).
A. Mehdizadeh Dehkordi, S. Bhattacharya, T. Darroudi, J.W. Graff, U. Schwingenschlögl, H.N. Alshareef, and T.M. Tritt: Large thermoelectric power factor in Pr-doped SrTiO3−δ ceramics via grain-boundary-induced mobility enhancement. Chem. Mater. 26, 2478 (2014).
A.M. Dehkordi, S. Bhattacharya, J. He, H.N. Alshareef, and T.M. Tritt: Significant enhancement in thermoelectric properties of polycrystalline Pr-doped SrTiO3−δ ceramics originating from nonuniform distribution of Pr dopants. Appl. Phys. Lett. 104, 3 (2014).
P. Puneet, R. Podila, M. Karakaya, S. Zhu, J. He, T.M. Tritt, M.S. Dresselhaus, and A.M. Rao: Preferential scattering by interfacial charged defects for enhanced thermoelectric performance in few-layered n-type Bi2Te3. Sci. Rep. 3, 1 (2013).
F. Liu, L. Hu, M. Karakaya, P. Puneet, R. Rao, R. Podila, S. Bhattacharya, and A.M. Rao: A micro-Raman study of exfoliated few-layered n-type Bi2Te2.7Se0.3. Sci. Rep. 7, 16535 (2017).
B. Khasimsaheb, S. Neeleshwar, M. Srikanth, S. Bathula, B. Gahtori, A.K. Srivsatava, A. Dhar, A. Sankarakumar, B.K. Panigrahi, S. Bhattacharya, R. Polida, and A.M. Rao: Thermoelectric properties of spark plasma sintered lead telluride nanocubes. J. Mater. Res. 30, 1 (2015).
K. Momma and F. Izumi: VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data. J. Appl. Crystallogr. 44, 1272 (2011).
W. Kraus and G. Nolze: POWDER CELL - A program for the representation and manipulation of crystal structures and calculation of the resulting x-ray powder patterns. J. Appl. Crystallogr. 29, 301 (1996).
A. Boultif and D. Louër: Powder pattern indexing with the dichotomy method. J. Appl. Crystallogr. 37, 724 (2004).
A.L. Pope, B. Zawilski, and T.M. Tritt: Description of removable sample mount apparatus for rapid thermal conductivity measurements. Cryogenics (Guildf). 41, 725 (2001).
G. Li and J.R. Gladden: High temperature resonant ultrasound spectroscopy: a review. Int. J. Spectrosc. 2010, 1 (2010).
W. Gong, H. Yun, Y.B. Ning, J.E. Greedan, W.R. Datars, and C.V. Stager: Oxygen-deficient SrTiO3−x, x = 0.28, 0.17, and 0.08. crystal growth, crystal structure, magnetic, and transport properties. J. Solid State Chem. 90, 320 (1991).
T.M. Tritt: Thermoelectric phenomena, materials, and applications. Annu. Rev. Mater. Res. 41, 433 (2011).
A. Migliori, J.L. Sarrao, W.M. Visscher, T.M. Bell, M. Lei, Z. Fisk, and R.G. Leisure: Resonant ultrasound spectroscopic techniques for measurement of the elastic moduli of solids. Phys. B: Condens. Matter 183, 1 (1993).
J. Callaway: Model for lattice thermal conductivity at low temperatures. Phys. Rev. 113, 1046 (1959).
P. Klemens: Thermal resistance due to point defects at high temperatures. Phys. Rev. 119, 507 (1960).
P.G. Klemens: Phonon scattering by oxygen vacancies in ceramics. Phys. B: Condens. Matter 263-264, 102 (1999).
W.G. Nilsen and J.G. Skinner: Raman spectrum of strontium titanate. J. Chem. Phys. 48, 2240 (1968).
D.A. Tenne, I.E. Gonenli, A. Soukiassian, D.G. Schlom, S.M. Nakhmanson, K.M. Rabe, and X.X. Xi: Raman study of oxygen reduced and re-oxidized strontium titanate. Phys. Rev. B - Condens. Matter Mater. Phys. 76, 1 (2007).
The research was supported by KAUST-Clemson Faculty Initiated collaboration grant. The authors would like to thank W.G. Nilsen and J.G. Skinner for the reprint their Raman spectra to directly compare with our Raman spectra. The authors would like to acknowledge useful discussions with Dr. Colin McMillen (Clemson University) on the XRD analysis of these samples and Mr. Herbert Behlow on stoichiometric analysis.
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Dehkordi, A.M., Bhattacharya, S., Darroudi, T. et al. Optimizing thermal conduction in bulk polycrystalline SrTiO3−δ ceramics via oxygen non-stoichiometry. MRS Communications 8, 1470–1476 (2018). https://doi.org/10.1557/mrc.2018.220