Relaxor Ferroelectric Oxides: Concept to Applications

Abstract

Ferroelectric ceramic is one of the most important functional materials, which has great importance in modern technologies. A ferroelectric ceramic simultaneously exhibits dielectric, piezoelectric, ferroelectric, and pyroelectric properties. The inherent ferroelectric properties are directly related to long-range electric dipoles arrangement in the ferroelectric domains and its response to external stimuli. However, the interruption of the long-range ordering of dipoles leads to the formation of a special class of material is known as relaxor ferroelectric. It shows quite different physical properties as compared to ferroelectric (normal ferroelectric). The origin and design of relaxor ferroelectric are quite interesting for fundamental perspective along with device applications. Therefore, the origin of relaxor ferroelectric along with its fundamental understanding for possible future applications, have been explained briefly in the present chapter.

Giant Polarization in Quasi‐Adiabatic Ferroelectric Na+ Electrolyte for Solid‐State Energy Harvesting and Storage

“…Because of their mild E b , large P max , and low P r dielectric bulk ceramics, antiferroelectrics, and relaxor ferroelectrics are likely the best candidates for electrical energy storage devices [21][22][23] . Some properties of antiferroelectrics restrict their technological uses, such as limited usage mainly due to hazardous lead nature and shorter life cycles, i.e., degradation of antiferroelectrics behavior with time [34] .…”

Critical Insight into Pretransitional Behavior and Dielectric Tunability of Relaxor Ceramics

“…Relaxor ceramics remain a cognitive challenge despite seven decades of research . The significance of innovative applications extends from varactors, signal tunable filters, phase shifters, and frequency-selective surfaces for conformal antennas to possible electrocaloric effect applications [12,14,16,21,27,28,34,35,41,[45][46][47][48][49][50][51]. Their unique dielectric properties, sensitivity to the external electric field, and tunability are essential.…”

“…The "homogeneous," canonic ferroelectric material is crucial as a reference case. In such a system, the temperature dependence of the dielectric constant ε(T) is represented by the Curie-Weiss (CW) equation [2][3][4][5]7,[9][10][11][12]14,16,19,21,24,25,28,[33][34][35]38,41,43]:…”

“…The next unique feature is related to strong changes in the dielectric constant when even a moderate external electric field is applied. This is described by the so-called tunability (T%) [9,12,[14][15][16]24,25,27,28,[34][35][36]41,43]:…”

“…For ferroelectric systems, including relaxors, temperature scans for subsequent frequencies lead to the manifestation of primary loss curves in ε ( f = const, T) plane. In this case, experimental data are portrayed via the following relation [1][2][3][7][8][9][10][12][13][14]21,24,32,35,47]:…”