458
16 Polarized Semiconductors
Fig. 16.9 Ferroelectric domains in a BaTiO 3 single crystal visualized by birefringence contrast. Reprinted with permission from [1499], ©1949 APS
(a)
PPLN
(b)
Fig. 16.10 a Scheme of PPLN (perodically poled lithium niobate), arrows denote the direction of spontaneous polarization. b Polarization microscopy image (vertical stripes are domains, horizontal dark lines are scratches)
Fig. 16.11 Temperature
dependence of the band
gap in BaTiO 3 (for
polarized light with
E ⊥ c). Experimental data
from [1500]
16.3.5 Optical Properties
The first-order phase transition of BaTiO 3 manifests itself also in a discontinuity of the band gap
(Fig. 16.11). The coefficient ∂ E g /∂ T for the temperature dependence of the band gap is also different
in the para- and ferroelectric phases.
16 Polarized Semiconductors
Fig. 16.9 Ferroelectric domains in a BaTiO 3 single crystal visualized by birefringence contrast. Reprinted with permission from [1499], ©1949 APS
(a)
PPLN
(b)
Fig. 16.10 a Scheme of PPLN (perodically poled lithium niobate), arrows denote the direction of spontaneous polarization. b Polarization microscopy image (vertical stripes are domains, horizontal dark lines are scratches)
Fig. 16.11 Temperature
dependence of the band
gap in BaTiO 3 (for
polarized light with
E ⊥ c). Experimental data
from [1500]
16.3.5 Optical Properties
The first-order phase transition of BaTiO 3 manifests itself also in a discontinuity of the band gap
(Fig. 16.11). The coefficient ∂ E g /∂ T for the temperature dependence of the band gap is also different
in the para- and ferroelectric phases.