Ferroelectric Phenomena in Crystals

Optical properties of A2B2C6 ferroelectrics-semiconductors: the effect of temperature and hydrostatic pressure

“…The / s P z ∂ ∂ value changes with temperature inside the incommensurate phase [26]. For instance, for the 2 2 6 Sn P Se crystals this fact is directly confirmed by the X-ray structural studies [26]. As a consequence, we can consider the parameters 0 α ′ and 0 E′ as dependent on temperature inside the incommensurate phase.…”

“…The 0 α , 0 E and σ values correspond to the paraelectric phase ( 0 s P = ). The / s P z ∂ ∂ value changes with temperature inside the incommensurate phase [26]. For instance, for the 2 2 6 Sn P Se crystals this fact is directly confirmed by the X-ray structural studies [26].…”

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

“…This chapter introduces the fundamental physics and concepts of dielectrics [30][31][32][33][34][35][36][37][38][39] and their classification [38][39][40][41][42][43][44][45][46] , as well as of ferroelectrics 2,16,29,[37][38][39][40][41][42][43][44][45][46][47][48][49][50] , and relaxor ferroelectrics. [51][52][53][54][55][56][57] The information of many textbooks and review papers related to the physics of materials science was employed throughout these sections.…”

“…This indicates a more pronounced decrease of the free energy anisotropy and enhanced properties. 39,159,192,193 It was pointed out that maximizing the number of coexisting phases near multicritical points leads to increased entropy and thus higher enhancement of electromechanical properties. 192 Point in Figure 2.16 exemplifies both a triple point and critical point, since a first order phase transition (solid line) leads to a second order phase transition (dashed line) as the temperature is increased.…”

“…A tricritical point, refers to the point where, at a fixed composition, the lines of critical points in the temperature-electric field-pressure phase diagram converge. 39 Therefore, their experimental determination is quite difficult. 156 The coincidence of a tricritical point with a triple point such as the one marked with in Figure 2.16, will only occur in the hypothetical case that the critical points in the temperature-electric field and electric field-pressure phase diagrams intersect at the same temperature-composition coordinates of the triple point (at zero electric field and atmospheric pressure).…”