Diffuse dielectric behaviour in Na0.5K0.5NbO3–LiTaO3–BiScO3 lead-free ceramics

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

“…However, this family of materials presents major synthesis difficulties that need to be overcome for entering a reliable large scale production. 284,285 The correct choice of reagents is critical since K 2 CO 3 is particularly sensitive to moisture. 279 A controlled atmosphere and humidity of the raw materials prior to calcination, during calcination, and also during sintering should be considered for obtaining the desired stoichiometry.…”

“…No dislocation contrast could be observed suggesting a semicoherent interface between the core and shell. 253,257,285,[422][423][424][425] It was demonstrated that dislocations, which lead to a gradual increase of incoherency, are a result of local strains. 426 This supports the findings of the XRD studies in the sintered samples ( Figure 5.33) considering that the beam coherence length (~ 80 nm) should allow partial detection of core and shell.…”

“…285,468 With the advent of nanotechnology, there has also been a continuous increase in organic and inorganic core-shell nanoparticle discoveries with exceptional properties. 8 This gave rise to the discovery of several types of core-shell microstructures, such as spherical 256,284,285,468 , hexagonal 469,470 , multiple cores within a single shell 471,472 , onion-like 473,474 , movable core within shell 475,476 , and 2-D structures such as rods [477][478][479] , among others. A general notation is described here in an attempt to standardize the nomenclature used to define core-shell microstructures.…”

High temperature dielectric ceramics: a review of temperature-stable high-permittivity perovskites

“…For the composition x = 0.07, a slightly narrower temperature-stable range occurred, with r = 630-700 ±15% from -15ºC to +300ºC [56,58]. Zhu et al, studied dielectric and piezoelectric properties in the system, (1-x)[0.98Na0.5K0.5NbO3-0.02BiScO3]-xLiTaO3 [60,61]. Values of r max decreased from an estimated 7000 at x = 0, to 2600 at x = 0.03LiTaO3.…”

Dielectric ceramic with stable relative permittivity and low loss from −60 to 300°C: A potential high temperature capacitor material

“…The materials are compositionally modified perovskites, ABO3 which incorporate Bi 3+ on A-sites [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] as reviewed in reference [21], for example (1-x)BaTiO3 -xBi(Mg0.5Ti0.5)O3 solid solutions [3][4][5][6][7]. The level of stability in r(T) for (1-x)BaTiO3 -xBi(Mg0.5Ti0.5)O3 becomes more pronounced with additional Ca 2+ substitution, giving r values ~ 1000 ± 15 % (1 kHz) from 80 -500 °C [3].…”