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Owada, Kenji; Shimomura, Susumu*; Nakao, Hironori*; Matsushita, Mitsuyoshi*; Namikawa, Kazumichi*; Mizuki, Junichiro
Journal of Physics; Conference Series, 320, p.012086_1 - 012086_5, 2011/09
Times Cited Count：0 Percentile：0.03(Physics, Condensed Matter)We have performed an X-ray photon correlation spectroscopy measurement of 91
Pb(Zn
Nb
)O
-9PbTiO and found a slow structural fluctuation in time near 
. The slow fluctuation consists of long-term and short-term fluctuations. We have derived the short-term fluctuation from the intensity fluctuations and found out the relaxation time to be an order of 10s. It is suggested that the slow fluctuation is owing to the competition between macroscopic tetragonal symmetry and the microscopic orthorhombic symmetry. The competition should be a main reason for the low-frequency dielectric permittivity.
Owada, Kenji; Namikawa, Kazumichi*; Shimomura, Susumu*; Nakao, Hironori*; Mimura, Hidekazu*; Yamauchi, Kazuto*; Matsushita, Mitsuyoshi*; Mizuki, Junichiro
Japanese Journal of Applied Physics, 49(2), p.020216_1 - 020216_3, 2010/02
Times Cited Count：3 Percentile：14.99(Physics, Applied)Owada, Kenji; Namikawa, Kazumichi; Mizuki, Junichiro; Matsushita, Mitsuyoshi*; Shimomura, Susumu*; Nakao, Hironori*; Hirota, Kazuma*
no journal, ,
no abstracts in English
Owada, Kenji
no journal, ,
We studied PNR of 91%Pb(ZnNb)O+9%PbTiO (PZN-9%PT) by means of coherent X-ray diffractions for obtaining the information concerning the function of PNR on relaxor. The sample PZN-9%PT is important material for industrial applications. We carefully studied PZN-9%PT around Tc and found behaviors of temperature dependence of diffuse scattering to be very similar to those of dielectric constants, including their hysteresis, for the first time. It clearly indicates that the dielectric constant is given by the one giving the diffuse scattering. The diffuse scattering, in this case, comes from PNRs. These results strongly suggest that the behavior of higher order structures, such as PNRs, is a key for understanding the relaxor phenomena i.e., large dielectric constants, dielectric dispersion and cubic-to-tetragonal phase transtition. Evolution and slowing down of the PNR towards Tc were also observed.
Owada, Kenji; Mizuki, Junichiro; Namikawa, Kazumichi*; Matsushita, Mitsuyoshi*; Shimomura, Susumu*; Nakao, Hironori*; Hirota, Kazuma*
no journal, ,
Owada, Kenji; Namikawa, Kazumichi*; Matsushita, Mitsuyoshi*; Mizuki, Junichiro*
no journal, ,
no abstracts in English
Owada, Kenji; Namikawa, Kazumichi*; Matsushita, Mitsuyoshi*; Mizuki, Junichiro*
no journal, ,
It is generally known that the temperature dependence of the dielectric constants of relaxor ferroelectrics near morphotropic phase boundary (MPB) shows a cooling-rate dependence. This is due to a domain fluctuation across a tetragonal-to-rhombohedral phase transition. In this paper, we focus on the tetragonal-to-rhombohedral phase transition (T
300 K) in relaxor ferroelectrics PZN-9%PT, which is very close to MPB. We have simultaneously measured the frequency-dependent dielectric constants and the coherent X-ray scattering directly reflecting a domain configuration. The results directly show an effect of the domain fluctuation on a low-frequency dielectric permittivity. These results should strongly relates to the cooling-rate dependence on the temperature dependence of the dielectric constants.
