著者
Sivasubramanian V. Tsukada S. Kojima S.
出版者
American Institute of Physics
雑誌
Journal of applied physics (ISSN:00218979)
巻号頁・発行日
vol.105, no.1, pp.014108, 2009
被引用文献数
9 4

The temperature dependences of acoustic phonon mode and the central peak have been investigated in Pb[(In1/2Nb1/2)0.65Ti0.35]O3 single crystal by Brillouin scattering. Longitudinal acoustic phonon begins to show marked softening below the Burns temperature TB~700 K. The longitudinal acoustic phonon mode exhibits clear anomalies at the cubic-tetragonal phase transition temperature of 540 K and at the tetragonal-rhombohedral one of 460 K. Below 600 K, the relaxation time calculated from the phonon mode agrees well with that of the broad central peak, suggesting a coupling between the local polarization and strain fluctuations of polar nanoregions. This temperature has been identified as another characteristic temperature T* besides TB, where the formation of long-lived polar nanoregions accompanied by the local strain fields governs the relaxation dynamics.
著者
Umeda T. Okonogi K. Ohyu K. Tsukada S. Hamada K. Fujieda S. Mochizuki Y.
出版者
American Institute of Physics
雑誌
Applied physics letters (ISSN:00036951)
巻号頁・発行日
vol.88, pp.253504, 2006-06
被引用文献数
25 18

The variable retention time phenomenon has recently been highlighted as an important issue in dynamic random access memory (DRAM) technology. Based on electrically detected magnetic resonance and simulation studies, we suggest that a single Si vacancy-oxygen complex defect is responsible for this phenomenon, when the defect is embedded in the near surface drain-gate boundary of a DRAM cell.