ترغب بنشر مسار تعليمي؟ اضغط هنا

Effect of polarization fatigue on the Rayleigh coefficients of ferroelectric lead zirconate titanate thin films: experimental evidence and implications

95   0   0.0 ( 0 )
 نشر من قبل Xiaojie Lou
 تاريخ النشر 2014
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

The effect of polarization fatigue on the Rayleigh coefficients of ferroelectric lead zirconate titanate (PZT) thin film was systematically investigated. It was found that electrical fatigue strongly affects the Rayleigh behaviour of the PZT film. Both the reversible and irreversible Rayleigh coefficients decrease with increasing the number of switching cycles. This phenomenon is attributed to the growth of an interfacial degraded layer between the electrode and the film during electrical cycling. The methodology used in this work could serve as an alternative non-destructive way for evaluating the fatigue endurance and degradation in dielectric properties of ferroelectric thin-film devices during applications.

قيم البحث

اقرأ أيضاً

Renewed interest has been witnessed in utilizing the piezoelectric response of $PbZr_{0.52}Ti_{0.48}O_{3}$ (PZT) films on glass substrates for applications such as data storage and adaptive optics. Accordingly, new methodologies are being explored to grow well-oriented PZT thin films to harvest a large piezoelectric response. However, thin film piezoelectric response is significantly reduced compared to intrinsic response due to substrate induced clamping, even when films are well-oriented. Here, a novel method is presented to grow preferentially (100)-oriented PZT films on glass substrates by utilizing crystalline nanosheets as seed layers. Furthermore, increasing the repetition frequency up to 20 Hz during pulsed laser deposition helps to tune the film microstructure to hierarchically ordered columns that leads to reduced clamping and enhanced piezoelectric response evidenced by transmission electron microscopy and analytical calculations. A large piezoelectric response of 280 pm/V is observed in optimally tuned structure which almost triples the highest reported piezoelectric response on glass. To confirm that the clamping compromises the piezoelectric response, denser films are deposited using a lower repetition frequency and a $BiFeO_{3}$ buffer layer resulting in significantly reduced piezoelectric responses. This paper demonstrates a novel method for PZT integration on glass substrates without compromising the large piezoelectric response.
Previous studies of Barkhausen noise in PZT have been limited to the energy spectrum (slew rate response voltages versus time), showing agreement with avalanche models; in barium titanate other exponents have been measured acoustically, but only at a mbient temperatures. In the present study we report the Omori exponent (-0.95$pm$0.03) for aftershocks in PZT and extend the barium titanate studies to a wider range of temperature.
212 - D. Phelan , X. Long , Y. Xie 2010
Neutron diffraction data obtained on single crystals of PbZr1-xTixO3 with x = 0.325 and x = 0.460, which lie on the pseudorhombohedral side of the morphotropic phase boundary, suggest a coexistence of rhombohedral (R3m/R3c) and monoclinic (Cm) domain s and that monoclinic order is enhanced by Ti substitution. A monoclinic phase with a doubled unit cell (Cc) is ruled out as the ground state.
Much attention has been given recently to flexible and wearable integrated-electronic devices, with a strong emphasis on real-time sensing, computing and communication technologies. Thin ferroelectric films exhibit switchable polarization and strong electro-mechanical coupling, and hence are in widespread use in such technologies, albeit not when flexed. Effects of extrinsic strain on thin ferroelectric films are still unclear, mainly due to the lack of suitable experimental systems that allow cross structural-functional characterization with in-situ straining. Moreover, although the effects of intrinsic strain on ferroelectric films, e.g. due to film-substrate lattice mismatch, have been investigated extensively, it is unclear how these effects are influenced by external strain. Here, we developed a method to strain thin films homogenously in-situ, allowing functional and structural characterization while retaining the sample under constant straining conditions in AFM and XRD. Using this method, we strained the seminal ferroelectric, PbZr0.2Ti0.8O3 that was grown on a flexible mica substrate, to reduce substrate clamping effects and increase the tetragonality. Consequently, we increased the domain stability, decreased the coercive field value and reduced imprint effects. This method allows also direct characterization of the relationship between the lattice parameters and nanoscale properties of other flexible materials.
The Landau theory of phase transitions of Ba0.8Sr0.2TiO3 thin film under external electric field applied in the planar geometry is developed. The interfacial van-der-Waals field Ez=1.1x10^8 V/m oriented normal to the film-substrate interface was intr oduced in to the model calculation to explain experimentally observed behavior of the polarization as a function of planar electric field. The Ez - misfit strain phase diagram of the film is constructed and discussed.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا