Ferroelectric domain structure of discrete PbTiO3 nanograins

Piezoelectric properties of individual nanocrystallites of Ba0.85Ca0.15Zr0.1Ti0.9O3 obtained by oxalate precursor route

“…† It is well known that the domain size has a strong dependence on crystallite size. [37][38][39] The low piezoelectric coefficient coupled with high coercive voltage (0.54 V) that is encountered for a 30 nm sized crystallite is ascribed to the lack of well-defined domain walls as these were expected to play a crucial role in the piezoelectric characteristics of the samples. These results suggest that, though the crystallites at the nanoscale exhibit piezoelectric phenomenon, one has to have large enough (450 nm) size to visualize reasonably good piezoelectric properties.…”

Optical and dielectric relaxor behaviour of Ba(Zr0.25Ti0.75)O3ceramic explained by means of distorted clusters

“…The main characteristics of relaxor ferroelectrics are the large, diffuse and frequency dispersive maximum in the temperature dependence of relative permittivity (ε) [7]. The relaxor behaviour has been studied in detail for lead-based perovskites, such as PbTiO 3 [8], Pb(Zr,Ti)O 3 [9] and Pb(Mg,Nb)O 3 [10]. However, these ceramics have serious drawbacks associated with the volatility and toxicity of PbO [11].…”

Dielectric Relaxation Phenomena in some Lead and Non-Lead Based Ferroelectric Relaxor Materials: Recent Advances

“…These are: (i) classical ferroelectrics with a sharp and strong peak in the temperature variation of dielectric permittivity and sharp or progressively vanishing spontaneous polarization (P s ) with increasing temperature related to either a first or second order phase transition (ii) Ferroelectrics with diffuse phase transition (DPT) characterized by a broad peak in the temperature dependence of dielectric permittivity with a frequency independent peak temperature (T m ) and, (iii) relaxor ferroelectrics or relaxors characterized by their broad dielectric transition with strong frequency dispersion in dielectric permittivity at the low temperature side of the peak, whereas the high temperature permittivity is almost frequency independent [2][3]. In the last few years, the dielectric and optical properties of relaxor ferroelectrics have been widely investigated for applications in wireless communications, metal-oxide-semiconductor field-effect transistors, and optical and microwave dielectrics [4][5][6][7][8][9][10][11]. The main characteristics of relaxor ferroelectrics are the large, diffuse and frequency dispersive peak in the temperature dependence of relative permittivity (ε′) at a temperature T m due to slowing down of dielectric relaxation [12], non-vanishing polarization above T m and slim hysteresis loop accompanied by no structural change at T m [13].…”