Evolution of the ferroelectric transition character of partially deuterated triglycine selenate

Abstract

Automatically recorded hysteresis loops and dielectric constant data on pure and partially deuterated triglycine selenate and sulphate are used to characterize the transition evolution from quasi-tricritical to clearly first order character. A quantitative assessment of the transition's displacive degree is made through the first anharmonic contribution to the effective field ( g ), obtained from hysteresis loop data. This characterization is complemented with the assessment by means of a generalized Rhodes-Wohlfarth parameter R = (NkB C /4 P 2 S 0 )1/2 involving the Curie constant C and the saturation spontaneous polarization. P S 0 as done previously by other authors.

Phase coexistence in highly deuterated ferroelectric triglycine selenate: Landau description

“…[1,2]. Recently, we performed a calorimetric study on the phase transition showing that the specific heat of the ferroelectric phase follows a classical tricritical Landau potential whose coefficients have been determined [3].The effect of deuteration on the dielectric properties of phase transition in TGSe has been previously investigated [4][5][6]. It has been found that the thermal hysteresis as determined from dielectric-constant measurements increases when the deuteration increases, which indicates that the transition becomes first order.…”

“…The effect of deuteration on the dielectric properties of phase transition in TGSe has been previously investigated [4][5][6]. It has been found that the thermal hysteresis as determined from dielectric-constant measurements increases when the deuteration increases, which indicates that the transition becomes first order.…”

Theoretical Study of Ferroelectric Triglycine Sulphate (TGS) Crystal in External Electric Fields

“… is dipole moment of O-H··O bond, E is external electric field, V is spin lattice interaction and A k and B k are position and momentum operators, ω k is the harmonic phonon frequency V (3) and V (4) are third and fourth order atomic force constant.…”

“…Recently Sun et al [3] have done growth and study about pyroelectric properties of pure and doped TGS crystal. Arago and Gonzalo [4] have done hysteresis curve studies of TGS crystal. Tolstekhina et al [5] have done atomic force microscopy domain structure on nano scale studies.…”

Aminoacid Containing Partially Deuterated Ferroelectrics

“…Our aim is to analyze the possible changes with composition [2] of the main ferroelectric parameters in these partially deuterated compounds using the effective field approach [3] that is, expressing the field that experiences each dipole as the external electric field applied and the mean contribution of all other dipoles in the crystal, E eff = E + βP.…”