Abstract
For further investigation on the defect structure of lithium niobate
(LiNbO3-hereafter LN) crystals using the neutron scattering technique, a
congruent lithium isotope niobate ((CLN)-L-7) crystal was grown by the
Czochralski method from a 48.4% Li-7 melt. The X-ray powder diffraction
(XRPD) results show that the as-grown crystal is a single-phased (Ft3c)
LN. We observed 4A(1)(TO)+7E(TO) Raman modes. The crystal composition
(Li mol%) determined from UV absorption edge and Raman measurements is
47.47% and 47.34%, respectively. The specific heat (C-p), thermal
diffusion coefficients (lambda(a), lambda(c)), thermal conductivities
(kappa(a), kappa(c)) and the average thermal expansion coefficients
(alpha(a), alpha(c)) were determined. The effect of Li vacancy content
is analyzed by comparing the results with those obtained for
stoichiometric lithium isotope niobate ((SLN)-L-7) and congruent natural
lithium niobate (CLN) crystals. The values of all thermal parameters of
(CLN)-L-7 are smaller than those of (SLN)-L-7 and CLN, which may be
related to either the difference of vacancy content or isotope
substitution. (C) 2010 Elsevier B.V. All rights reserved.
Users
Please
log in to take part in the discussion (add own reviews or comments).