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Home Material Sciences New Materials for Cryogenic Electromechanical Applications

New Materials for Cryogenic Electromechanical Applications

Objective

Objective is to provide new materials for electromechanical applications efficient at low temperatures:

  • target temperature range: 4 – 100 K
  • effects to be exploited: electrostriction, piezoeffect
  • material form: ceramics (polycrystalline)

The Main Problem

Conventional ferro-piezoelectrics: BaTiO3, PZT

Basic Properties

  • Piezoelectric properties appear in ferroelectric phases (below transition temperature TC)
  • Best performance as a rule is observed in the region that is close to TC
  • At cryogenic temperatures efficiency of these materials is lower by a factor of 5 – 10 compared to ambient conditions

Proposed Solution

Doped incipient ferroelectrics: SrTiO3:Ba; KTaO3:Li, Nb

Main features

  • Composition controlled transition temperature. (TC can be tuned from 0 to 200K)
  • Well understood behavior of single crystals
  • Ceramic samples (cheaper and more convenient than single crystals) have scarcely been studied
  • Share crucial features with advanced high-temperature piezoelectrics

Relevant Experience. Selected papers devoted to pure and doped incipient ferroelectrics

Theory:

  • Paraelectric relaxation and dynamics of the zero-field paraelectric resonance of noncentral ions B. E. Vugmeister and M. D. Glinchuk Sov. Phys. Solid State 17, 270 (1975)
  • Ferroelectric phase transition in crystals with noncentral ions B. E. Vugmeister and M. D. Glinchuk Sov. Phys. Solid State 21, 735 (1979)
  • Some features of the cooperative behavior of paraelectric defects in strongly polarizable crystals B. E. Vugme i ster and M. D. Glinchuk Sov. Phys. JETP 52, 482 (1980)
  • Dipole glass and ferroelectricity in random-site electric dipole systems B. E. Vugmeister and M. D. Glinchuk Rev. Modern. Phys. 62, 993 (1990)

Experiment:

  • Electric-field effect in ESR and local fields in KTaO3 I. N. Geifman, M. D. Glinchuk, and B. K. Krulikovski Sov. Phys. JETP 48, 741 (1978)
  • Investigation of the local phase transition in KTaO3:Fe3+ by means of the temperature broadening of the EPR lines I. P. Bykov, I. N. Ge i fman, M. D. Glinchuk, and B. K. Krulikovskii Sov. Phys. JETP 51, 386 (1980)
  • EPR evidence of extrinsic symmetry-breaking defects in nominally pure KTaO3 A. P. Pechenyi, M. D. Glinchuk, C. B. Azzoni, F. Scardina, and A. Paleari Phys. Rev. B 51, 12165 (1995)
  • Dipolar centers in incipient ferroelectrics: Mn and Fe in E. L. Venturini, G. A. Samara, V. V. Laguta, M. D. Glinchuk, and I. V. Kondakova Phys. Rev. B 71, 094111 (2005)

Tasks We Can Tackle

  • Preparation (in quantities sufficient for laboratory needs) of ceramics with usual average crystallite size of order of 2-5 mkm (properties similar to single crystals are expected)
  • Synthesis of ultrafinegrain ceramics with the same chemical composition. Average crystallite size up to 100 nm (new effects are predicted by the theory)
  • Express (preliminary) determination of relevant physical properties (dielectric spectra, electrostriction and piezoelectric coefficients)
  • Development of theoretical basis (or the adjustment of the existing one)

Areas of Application

New materials for electromechanical applications efficient at low temperatures

Contact Details

Glinchuk M.D., Head of Department of Functional Oxide Materials
Organization: Frantsevich Institute for Problems in Materials Science of NASU
Adress: 3, Krzhizhanovski str., Kyiv, Ukraine
+380(44)424-15-40
Fax.+380(44)424-15-40
This e-mail address is being protected from spambots. You need JavaScript enabled to view it

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