The Inorganic Fluoride and Oxyfluoride Ferroelectrics
Language
en
Article de revue
This item was published in
Journal de Physique III. 1997, vol. 7, n° 6, p. 1129-1144
EDP Sciences
English Abstract
The ferroelectric fluorides belong to six families of type (NH4)2BeF4, BaMnF4, SrAlF5, Na2MgAlF7, K3Fe5F15 or Pb5Cr3F19. The oxyfluorides can be separated in two groups: i) the true oxyfluorides with a relatively high F/O ...Read more >
The ferroelectric fluorides belong to six families of type (NH4)2BeF4, BaMnF4, SrAlF5, Na2MgAlF7, K3Fe5F15 or Pb5Cr3F19. The oxyfluorides can be separated in two groups: i) the true oxyfluorides with a relatively high F/O value (K3MoO3F3, Na5W3O9F5, Pb5W3O9F10, Bi2TiO4F2, ...); ii) the compositions derived from ferroelectric oxides (perovskite, tetragonal tungsten bronze, pyrochlore, LiTaO3, ...) characterized by a continuous F-O substitution. The phase transitions and the physical properties are discussed. The origin of the spontaneous polarization is described structurally. The variations of the Curie temperature with the type of substitution are related to chemical bonding. The potential interest of these materials for applications is briefly given.Read less <
English Keywords
Ferroelectrics
Oxyfluoride
Fluoride
Inorganic compounds
Origin
Hal imported