Shoichiro Kojima

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Structural phase transitions in relaxor ferroelectric materials remain to be one of the most puzzling issues in solid-state physics. In the present work, we have investigated relaxational and vibrational properties of a relaxor ferroelectric 0.71Pb(Ni<sub>1/3</sub>Nb<sub>2/3</sub>)O<sub>3</sub>-0.29PbTiO<sub>3</sub> single crystal by means of inelastic(More)
The critical behavior of a relaxor ferroelectric 0.7Pb(Sc<inf>1/2</inf>Nb<inf>1/2</inf>)O<inf>3</inf>-0.3PbTiO<inf>3</inf> (PSN-0.3PT) crystal is studied by the broadband micro-Brillouin scattering. Remarkable and continuous elastic anomaly is observed in the vicinity of the Curie temperature T<inf>C</inf>=500 K. The integrate intensity of a central peak(More)
We have studied the aging effect of bismuth sodium titanate (BNT) ceramics with point defects. With aging BNT ceramics, we have observed slight decrease in BNT permittivity. Permittivity vs. aging time is well reproduced by assumed Debye-relaxation. It is found that there are two relaxation processes in this aging effect. The diffuseness of phase transition(More)