钛酸锶的热传导研究
Thermal Conductivity Studies of SrTiO₃

DOI: 10.12677/MS.2014.43012, PP. 73-79

Keywords: 钛酸锶，氧缺陷，热传导，德拜模型
SrTiO₃, Oxygen Vacancies, Thermal Conductivity, Debye Model

Full-Text   Cite this paper   Add to My Lib

Abstract:

为了研究氧缺陷对钛酸锶热传导过程的影响，利用高温高真空条件下对钛酸锶进行退火，用高温型差示扫描量热仪测出单晶钛酸锶退火前后钛酸锶的比热，利用激光导热仪测出它们的热扩散系数，计算出它们的热导率，比较它们之间的差异。之后结合德拜模型分析退火前后出现差异及比热和热导随温度变化的原因。通过理论分析和实验相结合，得知钛酸锶在退火后产生氧缺陷，有效地降低了钛酸锶的热导，并进一步验证了钛酸锶的热导性质符合德拜模型。
In order to study the influence of oxygen vacancies in SrTiO₃ on its thermal conductivity, SrTiO₃ single crystals were annealed in high temperature under vacuum. The thermal conductivities of the as-received and annealed samples were determined by measuring their specific heat Cp of the samples using Differential Scanning Calorimetry (DSC) and their thermal diffusivities using Laser Flash Apparatus (LFA). The analysis showed that oxygen vacancies were generated during annealing which led to lower thermal conductivity, and the thermal conductivity properties of SrTiO₃ conformed to the Debye model.

References

[1]	DiSalvo, F.J. (1999) Thermoelectric cooling and power generation. Science, 285, 703-706.
[2]	Bell, L.E. (2008) Cooling, heating, generating power, and recovering waste heat with thermoelectric systems. Science, 321, 1457-1461.
[3]	Joshi, G., Lee, H., Lan, Y., et al. (2008) Enhanced thermoelectric figure-of-merit in nanostructured p-type silicon germanium bulk alloys. Nano Letters, 8, 4670-4674.
[4]	Ohta, H., Sugiura, K. and Koumoto, K. (2008) Recent progress in oxide thermoelectric materials: p-TypeCa3Co4O9 and n-type SrTiO3？. Inorganic Chemistry, 47, 8429-8436.
[5]	Biswas, K., He, J., Zhang, Q., et al. (2011) Strained endotaxial nanostructures with high thermoelectric figure of merit. Nature Chemistry, 3, 160-166.
[6]	Lee, S., Yang, G., Wilke, R.H.T., et al. (2009) Thermopower in highly reduced n-type ferroelectric and related perovskite oxides and the role of heterogeneous nonstoichiometry. Physical Review B, 79, Article ID: 134110.
[7]	Wang, H.C., Wang, C.L., Su, W.B., et al. (2011) Doping effect of La and Dy on the thermoelectric properties of SrTiO3. Journal of the American Ceramic Society, 94, 838-842.
[8]	Ohta, S., Nomura, T., Ohta, H., et al. (2005) High-temperature carrier transport and thermoelectric properties of heavily La-or Nb-doped SrTiO3 single crystals. Journal of Applied Physics, 97, Article ID: 034106.
[9]	Callaway, J. and Von Baeyer, H.C. (1960) Effect of point imperfections on lattice thermal conductivity. Physical Review, 120, 1149-1154.
[10]	Jeng, M.S., Song, D., Chen, G., et al. (2008) Modeling the thermal conductivity and phonon transport in nanoparticle composites using Monte Carlo simulation. Journal of Heat Transfer, 130, Article ID: 042410.
[11]	Yu, C., Scullin, M.L., Huijben, M., et al. (2008) Thermal conductivity reduction in oxygen-deficient strontium titanates. Applied Physics Letters, 92, Article ID: 191911.
[12]	Qiu, L.Y. and White, M.A. (2001) The constituent additivity method to estimate heat capacities of complex inorganic solids. Journal of Chemical Education, 78, 1076.
[13]	Kittel, C. and McEuen, P. (1986) Introduction to solid state physics. Wiley, New York.
[14]	Lee, J. and Demkov, A.A. (2008) Charge origin and localization at the n-type SrTiO3/LaAlO3 interface. Physical Review B, 78, Article ID: 193104.
[15]	Kurosaki, K., Kosuga, A., Muta, H., et al. (2005) Thermoelectric properties of thallium compounds with extremely low thermal conductivity. Materials Transactions, 46, 1502-1505.
[16]	Huang, J.D., Kuok, M.H., Lim, H.S., et al. (2003) Velocity angular dispersion of surface and bulk acoustic modes in SrTiO3. Journal of Applied Physics, 94, 7341-7344.

Full-Text