Ferroelectricity in lead monohydrogen phosphate, PbHPO4, and the deuterated form, PbDPO4

Thermodynamics and dynamical properties of the KH_{2}PO_{4} type ferroelectric compounds. A unified model

“…In the CsH 2 PO 4 type ferroelectrics, the proton ordering on hydrogen bonds is quasi-one-dimensional (see [34][35][36][37][38][39][40]). The same holds for PbHPO 4 ferroelectrics (see [41][42][43][44]). In the RbD 2 PO 4 ferroelectrics the system of hydrogen bonds changes even more, and two phase transitions take place [45].…”

Urbach tail for ferroelectric materials with an order-disorder-type phase transition

“…The ferroelectric transition occurs at T c ϭ310 K. This transition is a second-order one, and the spontaneous polarization P s slowly rises below T c . [17][18][19] It is known that the one-dimensional ordering of protons between the two stable configurations of O-H-O bonds is a primary cause of this phase transition. 18 Although displacements of heavy ions are also observed, its temperature dependence is not directly correlated with that of P s .…”

Time-resolved photoluminescence of hydrogen-bonded ferroelectrics PbHPO4

“…The spontaneous polarization P S rises slowly with temperature below T C to saturation at $T C -130 K (180 K). The advantage of targeting LHP is that the hydrogen bond linking PO 4 3À tetrahedra in quasi-one-dimensional network are separated by Pb 2+ ions [1], which is in contrast to the wellknown KDP with three-dimensional linkage of the hydrogen bond. This simple crystal structure of LHP has been taking an appeal to many researchers as a reference material to understanding of proton ordering in hydrogen-bonded ferroelectrics [2][3][4][5].…”

“…The LHP crystal undergoes a second-order phase transition from monoclinic Pc in the ferroelectric phase to monoclinic P2/c in the paraelectric phase at transition temperature T C =310 K [1]. The spontaneous polarization P S rises slowly with temperature below T C to saturation at $T C -130 K (180 K).…”