A bibliographical review of the high pressure studies of ferroelectric phase transitions

Abstract

A brief review of the various high pressure studies on the phase transitions in ferroelectric crystals carried out over the past two decades is presented. The theoretical framework in which high pressure studies have to be viewed is given. The pressure data of ferroelectric crystals are organized in the form of tables. High pressure spectroscopic and structural studies are included. The review contains a bibliography of over two hundred references.

Ferroelectricity and Pressure-Induced Phenomena Driven by Neutral Ionic Valence Instability of Acid–Base Supramolecules

“…Both the Phz-H 2 ba and deuterated Phz-D 2 ba reveal the similar pressure-dependence of T c I : monotonic increase at low-pressure region and saturation at high pressures beyond ∼1.0 GPa. The respective slopes of d T c I /d p = +180 and +200 K/GPa near p = 0 GPa are much higher than those of hydrogen-bonded ferroelectric KH 2 PO 4 (KDP, −46 K/GPa) and its family (−14∼ −140 K/GPa); this manifests high sensitivity to the pressure in this molecular compound family. The phase diagrams (Figure b,c) are more complicated in the low- p and - T region than that of Phz-H 2 ca.…”

“…On the other hand for Phz-H 2 ba and Phz-D 2 ba crystals, the anomalies at T c IC and T c II showed the complicated changes, initially positive, then negative, and again positive temperature shifts with pressure, in contrast to the monotonous increase of T c I , as shown in Figure 5. I /dp = +180 and +200 K/GPa near p = 0 GPa are much higher than those of hydrogen-bonded ferroelectric KH 2 PO 4 (KDP, −46 K/GPa) and its family (−14∼ −140 K/GPa); 23 this manifests high sensitivity to the pressure in this molecular compound family. The phase diagrams (Figure 6b,c The anisotropic nature of dielectric properties was also examined by applying the ac electric field E perpendicularly to the crystallographic (101̅ ) plane, which lies approximately along the hydrogen-bonded chains.…”

The effect of uniaxial pressure on the ferroelectric phase transition of TGSe crystals

“…Application of uniaxial pressure to a particular axis affects simultaneously all NHO and OHO bonds. Pressure applied along the a * -axis elongates the 'short' bond and shortens the 'long' and NH (12)O bonds, which may give rise to a slight downwards shift of T c , moving the character of the PT in the direction of the PT of first-order character (see figures 3,5). Uniaxial pressure applied along the c-axis elongates the 'long' and NH (12)O bonds and shortens the 'short' bond giving rise to an upwards shift of T c , moving it in the direction of the PT of second-order character.…”

“…Hydrostatic pressure-(p-) induced TCP have been observed for KDP, BaTiO 3 , PbTiO 3 and other ferroelectric crystals, as summarized in reviews by Srinivasan et al [5] and Gesi [6]. Uniaxial pressure (X) induces a change † from a first-order to a second-order PT for RbCaF 3 [7], KMnF 3 [8], and SrTiO 3 [9].…”

Effects of Glass Elements on the Structural Evolution ofin situGrown Ferroelectric Perovskite Crystals in Sol-gel Derived Glass-ceramics

“…When samples are annealed at low temperatures, the grain sizes of the samples are smaller. [33][34][35] Thus, both the small size effect and the stress effect are not responsible for the up-shift of the Curie point in the glass-ceramics. 31,32 In contrast, it is interesting to note that (i) the Curie points of BTBS and BTAS glass-ceramics are considerably higher than that of the BaTiO 3 ceramic, (ii) the Curie temperatures in the BTBS and BTAS Table V).…”