Light-induced metastable states in ferroelectric oxides

Synthesis and Characterization of K-Ta Mixed Oxides for Hydrogen Generation in Photocatalysis

“…Next, the samples were investigated by means of Raman spectroscopy ( Figure 5). [17,18]. Moreover, for K-650 the Raman peaks at ∼253 cm −1 and ∼711 cm −1 assigned to Ta 2 O 5 are not detected which means that their concentration is beyond the detection limit of Raman spectroscopy.…”

Ferroelectric Phase Transition and Photoinduced Cooperative Phenomena in Bi-Layered Perovskite Pb2Bi4Ti5O18 Ceramics Studied by Brillouin Scattering

“…7) The mechanism of the photoinduced dielectric response should originate from localized nonequilibrium electrons and itinerant electrons in an electron-phonon coupled system. [13][14][15][16][17][18][19][20][21][22] The instability of the soft-mode behavior in Ni-doped KTaO 3 observed owing to the local breaking symmetry has been reported under UV irradiation in a DC electric field. 23) From the viewpoint of instability in the soft mode, nonequilibrium electrons induced by photoexcitation are expected to affect the softmode dynamics in ferroelectrics near the phase transition point.…”

Ultraviolet Photoexcited Soft Mode Dynamics in Quantum Paraelectrics KTaO3Doped with Nickel

“…The mechanism of the photoinduced dielectric response should originate from a localized nonequilibrium electron and an itinerant one in an electron-phonon coupled system under UV photoirradiation. [21][22][23][24][25][26][27][28] Under UV photoirradiation, these quantum paraelectric compounds should take an excited state composed of nanoscale structures with polarons. If the photoinduced phenomenon in the dielectric property originates from an intrinsic nanostructure, conventional approaches, such as the application of the Maxwell-Wagner model in macroscopic two-component systems, are not suitable for the mechanism of the photoinduced dielectric property.…”