Dielectric Constant of PbTiO₃ Crystals in Sub-Kelvin Temperature Region

抄録

One of the glass-like behaviors, i.e. the frequency dependent minimum of the dielectric constant ε′ in milli-Kelvin region in PbTiO₃ has been measured as a function of grain size. The slope (dε′⁄dT) in the region T<T_min first increases with grain size, shows a distinct maximum at the grain size 10² nm, then decreases, where T_min is the temperature giving the dielectric constant minimum. This result strongly suggests that a large ideal perfect single crystal of PbTiO₃ will not show any glass-like behavior.