PUB-2014-HTE

High temperature elastic constants of rare-earth doped Sr0.9 X0.1 TiO3-δ (X= Pr, Y)

J. R. Gladden, S. P. Tennakoon, R. Adebisi, Qin Zhang, A.M. Dehkordi, S. Bhattacharya, T.M. Tritt, HN Alshareef, “High temperature elastic constants of rare-earth doped Sr0.9 X0.1 TiO3-δ (X= Pr, Y)”
J. Acoust. Soc. Am. 134, 4101 (2013)
J. R. Gladden, S. P. Tennakoon, R. Adebisi, Qin Zhang, A.M. Dehkordi, S. Bhattacharya, T.M. Tritt, HN Alshareef
High temperature elastic constants
2013
Temperature dependence of the elastic constants of polycrystalline rare-earth doped strontiumtitanate (STO) [ SrXTiO (X = Pr, Y)] was investigated in the temperature range of 300 K—750 K using resonant ultrasound spectroscopy. Elastic constants of undoped STO decrease linearly indicating typical softening with increased temperature. Yttrium (Y) doped STO also exhibits a monotonic softening, however, with a pronounced curvature in this high temperature regime. Trends of elastic constants of the praseodymium (Pr) doped STO show a non-monotonic stiffing from room temperature to 475 K, followed by a gradual softening. Changes in attenuation were quantified by the inverse quality factor (1/Q) averaged over measured resonances. Undoped STO showed a monotonic gradual increase of attenuation with increasing temperature whileyttrium doped STO showed little variation. In contrast, attenuation of Pr doped STO exhibited a peak around 425 K. These results will be compared to thermal conductivity measurements in the same temperature range and phonon scattering mechanisms will be discussed.