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processes of switching of crystals SBN

As, as it has been scored in operation [39], action of variation fields makes essential impact on a state polar nanoklasterov in relaksornyh a ferroelectric material special interest has examinations of processes of switching.

The dielectric hysteresis of various compositions of crystals SBN in variable electric fields was studied by many authors [38, 62, 65-73].

In operation [38] it is shown, that dynamics of loops of the dielectric hysteresis of crystals SBN differs from dynamics of loops in a modelling ferroelectric material (fig. 1.16). Hysteresis curves have a bastard appearance, and the first cycles at all are unlocked. To be reproduced loops begin only after several cycles of switching. The abnormal behaviour of loops
The dielectric hysteresis of crystals SBN authors [38] contacts degradation on temperature makismuma an inductivity.

Fig. 1.16. Quasi-static loops of the dielectric hysteresis of crystals TGS (a), SBN: (La+Ce) (b), SBN:Nd (), SBN:Cr (d), PMN () at temperatures 293, 274, 273, 206 and 210 To accordingly. On a parenthesizing - a local free energy as function of polarisation [38].

Examination of loops of the dielectric hysteresis on frequency of 50 Hz, has shown, that crystals SBN61 have a threshold of an external field of 4,4 kv/sm at which achievement sharp growth of quantity of polarisation and reduction of a coercive field [68 is observed, 72, 73]. Such abnormal behaviour of a loop of the dielectric hysteresis, the author [72] relates to behaviour of an inductivity in variable electric fields, namely: magnification of value of an inductivity from 10 (in the field intensity of 0,8 kv/sm) to 1 0i (bполе 4,8 kv/sm).

In operations [68, 72] also it is shown, that the loop of the dielectric hysteresis for SBN61 degenerates in an ellipse of losses at order temperature 60С, that authors speaks sharp magnification of conductivity of data

Material (fig. 1.17).

Fig. of 1.17 Loops of the dielectric hysteresis in pure crystal SBN at temperatures 35С (), 52С () and 65С () [72].

Authors [81] score presence of the phenomenon of effect of weariness at crystals SBN that was shown in degradation of hysteresis curves at consecutive cycles of switching.

1.4.4.

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A source: Lisitsyn Vladimir Sergeevich. PYROELECTRIC PROPERTIES And the STATE of POLARIZATION of MONOCRYSTALS of FIRM SOLUTIONS NIOBATA of BARIUM of STRONTIUM And NIOBATA CALCIUM BARIUM. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2015. 2015

More on topic processes of switching of crystals SBN:

  1. ferroelectric properties of crystals SBN
  2. domain structure of crystals SBN
  3. З.1. Temperature dependences pirotoka crystals SBN of a various composition
  4. influence of impurities on physical properties of crystals SBN
  5. 4.1. Influence of a temperature cycling on a state of polarisation of crystals SBN
  6. crystalline structure of crystals SBN
  7. properties of crystals SBN
  8. optical properties of the uniaxial crystals paratellurita, iiobata lithium and SBN, as objects for examinations by a conoscopy method
  9. the Analysis of a variance of processes of switching
  10. switching Processes in pulsing fields in the form of a meander
  11. switching Processes in sinusoidal fields of different frequencies
  12. switching Processes in fields frequency of 50 Hz
  13. 3.2. The analysis of processes of magnetisation ortorombicheskih crystals