Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Disordered systems ferroelectric crystals

Burrows AD (2004) Crystal Engineering Using Multiple Hydrogen Bonds 108 55-96 Bussmann-Holder A, Dalai NS (2007) Order/Disorder Versus or with Displacive Dynamics in Ferroelectric Systems. 124 1-21... [Pg.219]

Section 4 is entirely devoted to ferroelectric and H-bonded systems. It also provides a nice illustration of results that always maintained the utility of proton NMR in solid state, even wideline, or how the old question of the order disorder or displacive nature of some ferroelectric phase transitions were reopened by progresses in NMR resolution. A number of structural phase transition is discontinuous, but the examples of coexistence in solid-state and kinetic studies are rather scarce this is the object of Section 5. Section 6 is devoted to single-crystal studies that allow very precise comprehension of subtle phase transition mechanisms. Section 7 introduces the salient features of NQR that represent an interesting alternative to NMR in some cases. The section ends with a table of miscellaneous phase transitions that complete the references given in the text. Section 8 concludes and presents some perspectives in NMR phase transition studies. [Pg.122]

Let us consider the system of electric dipoles and other defects randomly distributed in the film paraelectric phase. Similarly to the random field model for bulk relaxor ferroelectrics [83], this phase is called Burns reference phase. For example, the relaxor ferroelectric Pbo,92Lao,osZro,65Tio,3503 (PLZT) (where La ions are the main sources of random field) is known to have the Burns phase simply as the paraelectric phase of PbZro,65Tio,3s03 (PZT). Latter phase exists at T > Tj, Td is so-called Burns temperature and Td = 1), where Tc is transition temperature form paraelectric to ferroelectric phase in PZT. The indirect interaction of electric dipoles via soft phonon mode of a host crystal tends to order the system and so to generate the ferroelectric phase in it [84]. However, the direct interaction of dipoles and other defects like point charges, try to disorder a system, transforming it into relaxor ferroelectric. [Pg.132]


See other pages where Disordered systems ferroelectric crystals is mentioned: [Pg.149]    [Pg.260]    [Pg.582]    [Pg.740]    [Pg.77]    [Pg.93]    [Pg.3]    [Pg.49]    [Pg.44]    [Pg.368]    [Pg.483]    [Pg.118]    [Pg.52]    [Pg.115]    [Pg.368]   
See also in sourсe #XX -- [ Pg.44 , Pg.45 , Pg.46 , Pg.47 ]

See also in sourсe #XX -- [ Pg.44 , Pg.45 , Pg.46 , Pg.47 ]




SEARCH



Crystal disorder

Crystal systems

Crystallizing system

Disordered ferroelectrics

Disordered systems

Ferroelectric crystals

Ferroelectric system

Ferroelectric system ferroelectrics

Ferroelectricity crystals

© 2024 chempedia.info