Brillouin scattering study of the ferroelectric phase transition in tris-sarcosine calcium chloride

Abstract

Brillouin spectra from longitudinal phonons in ferroelectric tris-sarcosine calcium chloride propagating along [100], [010], and [001] have been measured as functions of temperature. Large anomalies were found in the Brillouin shift and hnewidth in the [100] and [001] phonons. These anomalies are interpreted as arising from the linear coupling of the polarization and the phonons. From the temperature where the linewidth is maximum, the relaxation time of the polarization fluctuations is estimated to be~=3. 1X10 ' /(T,-T) sec, where T, is the ferroelectric transition temperature. We also observed anomalies in Brillouin shift and linewidth of the [010] phonons which propagate along the ferroelectric b axis. These anomalies are interpreted as coming from electrostrictive coupling. The energy-relaxation time was estimated to be~E-2.5&(10 ' /(T-T,) sec in the paraelectric phase and~E-1.0& 10 /(T,-T) sec in the ferroelectric phase, by comparing our Brillouin results with those of the ultrasonic measurements.

Hypersonic studies in CsD2AsO4 and Cs0.84(ND4)0.16D2AsO4 single crystals

“…As the temperature decreases, DCDA shows a discontinuous change in frequency shift near ¹ associated with a sharp damping peak at ¹& 203 K. If the phase transition were second order, the phonon frequency should show a continuous variation as ¹P¹! like other ferroelectric crystals TGS (triglycine sulfate) and TSCC (tris-sarcosine calcium chloride) [8,9]. Thus, such an abrupt behavior in frequency confirms that DCDA possesses a first-order structural transition.…”

Phases in antiferroelectric-sideRb1−x(ND4)Tu1, Gao2, Jaw3 et al. 1998Phys. Rev. BSelf Cite61120View full textAdd to dashboardCite

“…The Landau-Khalatnikov maximum usually occurs near T c and can be used as an indication of a long-range order FE or AFE phase transition. 3,13,14 To determine the relation between phase characteristic and ammonium concentration, the low-temperature spectra from scattering geometries A 1 -y(zz)x and E-y(xz)x were measured for xϭ1.0, 0.69, 0.55, and 0.39, and are given in Figs. 5͑a͒-5͑b͒, respectively.…”

1H NMR study of the phase transitions of trissarcosine calcium chloride single crystals at low temperature

“…A new phase transition at 65 K was discovered using measurements of the specific heat [4]. The physical properties of this crystal have already been studied by several methods, including X-ray [1], dielectric and calorimetric measurements [5], Brillouin scattering [6][7][8], and infrared and Raman spectroscopy [9][10][11]. Several magnetic resonance methods have also been used, including electron paramagnetic resonance (EPR) [12,13], electron nuclear double resonance (ENDOR) [14], and nuclear magnetic resonance (NMR) [15][16][17][18][19][20].…”