Nonlinear dielectric properties of amorphous Bi1.8Pb0.3Sr2Ca2Cu3−x KxOz (x = 0.2–0.3)

Ferroelectricity in the glassy material of the composition Bi2O3–Pb3O4–CuO–K2O

“…Curie's point T C . This transition was observed previously for glasses of comparable composition with the addition of CaO and SrO [12][13][14] and was confirmed by others [16][17][18][19][20] as well.…”

“…Verification of these results of ferroelectricity in glasses of the same composition were published recently [16][17][18][19][20]. However, according to transmission electrons micrographs, TEM, Mukherjee et al [16][17][18] interpreted the confirmed ferroelectricity as due to nanocrystalline clusters 10-50 nm in size [16][17][18] containing particles of size less than 10 nm precipitated in their own samples.…”

“…Furthermore, by applying Maxwell-Wagner polarization of heterogeneous components [14] on Mukherjee et al micrograph results [16][17][18], it was predicted that the observed ferroelectricity is duo to the glassy part of their sample [14]. In other publications by Geridnev and Repnikov [19,20] ferroelectricity was confirmed further in a similar set of samples, Bi 1.8 Pb 0.3 Sr 2 Ca 2 Cu 3−x K x O z (x = 0.1-0.4), by applying nonlinear dielectric measurements. It was revealed that the value of the dielectric constant decreased by a quadratic law as biased dc field strength is increased.…”

“…It was revealed that the value of the dielectric constant decreased by a quadratic law as biased dc field strength is increased. Such behavior of the dielectric permittivity under external bias electric field speaks in favor of a dielectric nonlinearity, which can be described in frames of a thermodynamic theory of ferroelectricity [19,20].…”