X-ray photon correlation spectroscopy of structural fluctuations in relaxor ferroelectrics PZN-9%PT

X線光子相関分光で調べるリラクサー強誘電体PZN-9%Pの構造揺らぎ

大和田 謙二; 下村 晋*; 中尾 裕則*; 松下 三芳*; 並河 一道*; 水木 純一郎

Owada, Kenji; Shimomura, Susumu*; Nakao, Hironori*; Matsushita, Mitsuyoshi*; Namikawa, Kazumichi*; Mizuki, Junichiro

91Pb(ZnNb)O-9PbTiOにおいてX線光子相関分光を行い、近傍において遅い構造揺らぎを見いだした。その遅い構造揺らぎは遅い成分と早い成分からなる。われわれは早い成分を抽出し10秒ほどの緩和時間を得た。これらの揺らぎはマクロな正方晶とミクロな射法対称性の競合によるものであり、低周波誘電率を与えるものであると推測される。

We have performed an X-ray photon correlation spectroscopy measurement of 91Pb(ZnNb)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.