Inhaltszusammenfassung

We have investigated the crystal structure and the ferroelectric properties of BaTiO3 thin *lms with YBa2Cu3O7?* as the bottom and Au as the top electrode. Epitaxial heterostructures of YBa2Cu3O7?* and BaTiO3 were prepared by dc and rf sputtering, respectively. The crystal structure of the *lms was characterised by X-ray di*raction. The ferroelectric behaviour of the BaTiO3 *lms was con*rmed by hysteresis loop measurements using a Sawyer Tower circuit. We obtain a coercive *eld of 30 kV/cm an...We have investigated the crystal structure and the ferroelectric properties of BaTiO3 thin *lms with YBa2Cu3O7?* as the bottom and Au as the top electrode. Epitaxial heterostructures of YBa2Cu3O7?* and BaTiO3 were prepared by dc and rf sputtering, respectively. The crystal structure of the *lms was characterised by X-ray di*raction. The ferroelectric behaviour of the BaTiO3 *lms was con*rmed by hysteresis loop measurements using a Sawyer Tower circuit. We obtain a coercive *eld of 30 kV/cm and a remanent polarisation of 1.25 *C/cm2. At sub-switching *elds the capacitance of the *lms obeys a relation analogous to the Rayleigh law. This behaviour indicates an interaction of domain walls with randomly distributed pinning centres. At a *eld of 5 MV/m we calculate a 3% contribution of the irreversible domain wall motion to the total dielectric constant.» weiterlesen» einklappen

Autoren

Klassifikation

DFG Fachgebiet:
Physik der kondensierten Materie

DDC Sachgruppe:
Physik