Scaling Parameters in Frustrated Systems: Spin Glasses and Relaxor Ferroelectrics

Abstract

The levels of 34S from 5.4 MeV to 7.3 MeV excitation energy have been studied by particle-? ray angular correlation experiments using the reaction 3'P(a, P )~~S .Spin assignments of 2, 3,4,4, 1, 2 and 2 have been made to the levels at 5.680, 6.173,6.250, 6.415, 6.480, 7.1 12 and 7.220 MeV respectively. Spin restrictions have been placed on other levels and some previous spin assignments have been confirmed. Branching ratios have been determined for many of the observed decay modes and multipole mixing ratios obtained for several transitions.

Structural and Dielectric Properties in (1−x)BaTiO3–xBi(Mg1/2Ti1/2)O3 Ceramics (0.1 ≤ x ≤ 0.5) and Potential for High‐Voltage Multilayer Capacitors

“…This trend of the freezing temperatures is also reported for BT–BS system where the freezing temperature also increases with the amount of BS . It is noteworthy that the activation energy varied between 0.17 and 0.22 eV and is exceptionally high compared to that of typical lead‐based relaxors, such as Pb(Mg 1/3 Nb 2/3 )O 3 . This high activation energy is consistent with the observed difference between the Burns temperature ( T d ) and the Vogel–Fulcher determined freezing temperature ( T f ), as pointed out earlier by Stringer et al .…”

“…The temperature at maximum permittivities ( T max ) increased quasi‐linearly with the increase in BMT concentration before a second phase appeared. The Vogel–Fulcher model fitted to dielectric relaxation of (1− x )BT– x BMT( x = 0.1–0.4) revealed the activation energy of 0.17–0.22 eV, which was high compared to that of typical lead‐based relaxors …”

Structure‐property relationships in BiScO3–PbTiO3–PbMg1/3Nb2/3O3 ceramics near the morphotropic phase boundary

“…There is a good correlation in E a and the temperature difference between T B and T VF . A similar trend was observed earlier in various relaxor ferroelectrics and spin glasses …”

Relaxing with relaxors: a review of relaxor ferroelectrics

“…On the other hand, at small concentrations of PT, the relaxation of the dielectric permittivity can be described by the Vogel-Fulcher law (Equation (5) with x = 0.1, the activation energy is 40.7 meV, the pre-exponential factor is 1.03 THz, and the static freezing temperature is T f = 291.5 K [180]. Generally this suggests that the higher the PT content, the larger the freezing temperature T f [181]. The transition from a relaxor to a conventional ferroelectric is continuous as the concentration x increases.…”