Low Temperature Thermal Conductivity of KTaO3 and KTN Single Crystals

  • A. M. de Goër
  • B. Salce
  • L. A. Boatner


The mixed crystals KTa1-x NbxO3 (KTN) are ferroelectrics with a transition temperature Tc which depends on the Nb content x. The phase diagram for small x, established by dielectric and elastic measurements1,2, shows that crystals with x < 0.8% remain paraelectric at all temperatures. We have measured the thermal conductivity K of several crystals with x varying from 0 to 3%, from 1.3 to 200 K and, in some cases, down to 80mK. The standard stationary flow method was used and the error in K is thought to be less than 7%. The single crystals were grown by means of a flux technique, using a high temperature (1430°C) reaction of Ta2O5, Nb2O5 and an excess of K2CO3. The material, which was contained in a platinum crucible, was held at the maximum temperature for approximately 12 hours, and then slowly cooled (1° to 3°C/hour) between 1430 and 950°C. Self-nucleation usually resulted in the production of 1 to 4 large grains. Cooling from 950°C to room temperature was accomplished in 8 to 10 hours and hot H2O was then used to remove the flux in order to free the crystals. The samples were cut, using a wire saw, as parallelepipeds with cross-sections about 2 × 2 mm2 and length 8 to 16 mm along 100 axis. Typical compositional inhomogeneities can be estimated to about 0.3%2.


Acoustic Phonon Phonon Scattering Mixed Crystal Residual Impurity Elastic Measurement 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    L.A. Boatner, U.T. Höchli et H. Weibel, Helv. Phys. Acta 50: 620 (1977).Google Scholar
  2. 2.
    U.T. Höchli, H.E. Weibel and L.A. Boatner, Phys. Rev. Letters 39 n° 18: 1158 (1977).Google Scholar
  3. 3.
    E.F. Steigmeier, Phys. Rev., 168 n° 2: 523 (1968).Google Scholar
  4. 4.
    H.H. Barrett and M.G. Holland, Phys. Rev. B 2, n° 8: 3441 (1970).Google Scholar
  5. 5.
    W.N. Lawless, Phys. Rev. B 16 n° 1: 443 (1977). A.J.H. Mante and J. Volger, Physica 52: 577 (1971).Google Scholar
  6. 6.
    A.J.H. Mante and J. Volger, Physica 52: 577 (1971).Google Scholar

Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • A. M. de Goër
    • 1
  • B. Salce
    • 1
  • L. A. Boatner
    • 1
    • 2
  1. 1.Centre d’Etudes Nucléaires de GrenobleS.B.T.Grenoble CedexFrance
  2. 2.Sol. State Div.O.R.N.L.Oak RidgeUSA

Personalised recommendations