Scaling and metastable behavior in uniaxial ferroelectrics

Abstract

Scaling and metastable behavior in uniaxial ferroelectricsFernández del Castillo, J.R.; Noheda, Beatriz; Cereceda, N.; Gonzalo, J.A.; Iglesias, T.; Przeslawski, J. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. J. PrzeslawskiInstitute of Experimental Physics, University of Wroclaw, Max Born Sr.,9, Poland ͑Received 15 July 1997͒Improved experimental resolution and computer aided data analysis of hysteresis loops at TϷT C in uniaxial ferroelectrics triglycene sulfate ͑ordinary critical point͒, and triglycine selenate ͑quasitricritical point͒ show that scaling holds in a wide range of scaled fields spanning many orders of magnitude, well beyond the asymptotic region (͉TϪT C ͉→0), and that the behavior of metastable experimental points (EϽ0,PϾ0) approaches the theoretical branch of the respective scaling equation as T→T C . ͓S0163-1829͑98͒05102-9͔

Specific heat of ferroelectric TGSe under electric field: analysis in terms of Landau theory

“…The internal field can be related to the previously reported idea that the effective field on the sample is the external field plus different terms depending on successively higherorder terms in the polarization, which can be attributed to dipolar, quadrupolar, octopolar, etc contributions [19]. It has been shown [11] that in the case of the tricritical phase transition in TGSe the derived equation of state is analogous to the corresponding one derived above from Landau theory (equation ( 2)) but it contains specific temperature dependence for the Q 5coefficient. Nevertheless, in the temperature interval under investigation (294 < T < 297, where the anomaly in the specific heat is significant), the variation of the coefficient of Q 5 with temperature is lower than ±1.5%, so it can be considered practically temperature independent.…”

“…The scaling equation of state which relates the polarization and the electric field has also been successfully investigated from hysteresis loop measurements [11], in terms of the generalized effective field approach developed by Gonzalo [12], which asymptotically gives the classical Landau theory at T = T c .…”

The transverse field effect in the triglycine sulphate ferroelectric

“…The influence of an electric field E parallel to the ferroelectric axis on dielectric properties of uniaxial ferroelectrics has been investigated in many papers (e.g. [1][2][3][4][5]). Strongly fielddependent electric susceptibility values were measured close to the critical point.…”

Equation of State for Ising Lattices

“…Of course we will be limited to more reduced sizes (smaller L's) as the dimensionality increases, but we have excellent experimental data [18] on a complete set of isotherms in uniaxial ferroelectric TGS to produce excellent scaling plots with T c = 321.470 and mean field critical exponents β = 1/2 and δ = 3. Support from the Spanish MECyD through Grant Number BFM2000-0032 is gratefully acknowledged.…”

“…Work is in progress to obtain Monte Carlo data in larger 3D Ising lattices at closer field/temperature intervals, and to extend the investigation of scaling plots in the vicinity of the transition to higher dimensionalities Ising 4D, Ising 5D, etc, in order to monitor closely how the approach to mean field behavior takes place. Of course we will be limited to more reduced sizes (smaller L's) as the dimensionality increases, but we have excellent experimental data [18] on a complete set of isotherms in uniaxial ferroelectric TGS to produce excellent scaling plots with T c =321.470 and mean field critical exponents β=1/2 and δ=3.…”