Synthesis and Dielectric Characteristics of the Layered Structure Bi_4‐xLn_xTi₃O₁₂ (Ln: Pr, Nd, Gd, Dy).

Abstract

Ln: Pr, Nd, Gd, Dy). -The title compounds are prepared by solid state reaction of mixtures of Bi2O3, TiO2, and Nd2O3, Pr6O11, Gd2O3, or Dy2O3 (900°C, 19 h). The samples are characterized by powder XRD, SEM, and impedance spectroscopy. They exhibit layered orthorhombic structures. The conductivity diminishes as the size of Ln increases. The rare earth concentration determines the ferroelectric characteristics of the compounds: for small x values they behave as typical ferroelectrics, but all of them tend to become relaxors with increasing x. -(PINEDA-FLORES*, J. L.; CHAVIRA, E.; REYES-GASGA, J.; GONZALEZ, A. M.; HUANOSTA-TERA, A.; J. Eur.

Ferroelectric properties of Bi3.4Ho0.6Ti3O12 thin films prepared by sol-gel method

“…But the BTO films show fatigue and unexpectedly low value of Pr, making the BTO films unsuitable for FeRAM applications. Recent reports reveal that the fatigue-free thin films with excellent ferroelectric properties can be obtained by the substitution of lanthanide ions, such as La 3+ , Pr 3+ , Ce 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Dy 3+ , and Gd 3+ ions for the Bi 3+ ions in the (Bi 2 Ti 3 O 10 ) 2− pseudoperovskite layers of BTO structure [2,[7][8][9][10][11][12][13][14][15][16] . The fatigue-free behavior of lanthanide-substituted BTO thin films can be attributed to the enhanced stability of oxygen in the TiO 6 octahedron cell, which is caused by the substitution of lanthanide ions for Bi 3+ located near the TiO 6 octahedron cell [2] .…”

Dielectric properties of bismuth titanate ceramics containing SiO2 and Nd2O3 as additives

“…It is well known, that the phase formation and the properties of Bi 4 Ti 3 O 12 ceramics are strongly influenced not only by the method of preparation, but also by the type and portion of additives. The introduction of Nd 2 O 3 as an additive allows the synthesis of materials with improved dielectric and ferroelectric properties, such as high dielectric constant, low dielectric losses, high remnant polarisation and high resistance to fatigue [7][8][9][10][11][12][13][14][15][16][17][18]. The other advantage of Nd 2 O 3 addition is the existence of solid solutions in the system Bi 2 O 3 -TiO 2 -Nd 2 O 3 .…”

The Nature of Dielectric Nonlinearity in the Region of Diffused Phase Transition in Layered Ferroelectric BaBi2Nb2O9

“…Apart from applied research, representations of the mechanisms of phase transitions in relaxor materials are being developed within the framework of evolving physics of disordered condensed media the features of which are distinctive to layered ferroelectrics [1,2]. A number of questions concerning the nature of unusual physical properties of layered ferroelectric relaxors still remain without answers.…”