Ferroelectric poly(vinylidene-fluoride) (PVDF) has, in the past, been proposed as an ideal candidate for data storage applications as it exhibits a bistable, remanent, polarization that can repeatedly be switched by an electric field. However, fabrication of smooth ferroelectric PVDF thin films, as required for microelectronic applications, is a long-standing problem. At present, the copolymer ...

The effect of electron irradiation on the ferroelectric properties ofLangmuir-Blodgett films of the copolymer poly(vinylidene fluoride-trifluoroethylene) isinvestigated using 1.26 MeV electrons with dosages from 16 to 110 Mrad. Films wereirradiated in the ferroelectric state to investigate the effect of defect introduction inultrathin films. Electron irradiation is known to ...

In this chapter we present an overview of some important concepts related to the processes and microstructural mechanisms that produce the deformation of hysteresis loops and the loss of their symmetry characteristics in ferroelectric, ferroelastic and ferromagnetic systems. The most discussed themes include: aging and fatigue as primary mechanisms of biased hysteresis loops in ferroelectric/fe...

Ferroelectric materials are known to be lossy at microwaves. A local microetching technique based on laser ablation is implemented here to reduce the insertion loss of highly tunable devices fabricated on KTa1−xNbxO3 (KTN) ferroelectric thin films. The relevance of this approach is studied in X-band by comparing numerically and experimentally the performance of a frequency-tunable coplanar wave...

Nanoscale electromechanical activity, remanent polarization states, and hysteresis loops in paraelectric TiO(2) and SrTiO(3) thin films are observed using scanning probe microscopy. The coupling between the ionic dynamics and incipient ferroelectricity in these materials is analyzed using extended Landau-Ginzburg-Devonshire (LGD) theory. The possible origins of electromechanical coupling includ...

The functional properties of two types of barium strontium titanate ~BST! thin film capacitor structures were studied: one set of structures was made using pulsed-laser deposition ~PLD! and the other using chemical solution deposition. While initial observations on PLD films looking at the behavior of Tm ~the temperature at which the maximum dielectric constant was observed! and Tc* ~from Curie...

We demonstrate a dramatic effect of film thickness on the ferroelectric phase transition temperature, Tc, in strained BaTiO3 films grown on SrTiO3 substrates. Using variable temperature ultraviolet Raman spectroscopy enables measuring Tc in films as thin as 1.6 nm, and film thickness variation from 1.6 to 10 nm leads to Tc tuning from 70 to about 925K. Raman data are consistent with synchrotron...

We have investigated the nanoscale switching properties of strain-engineered BiFeO(3) thin films deposited on LaAlO(3) substrates using a combination of scanning probe techniques. Polarized Raman spectral analysis indicates that the nearly tetragonal films have monoclinic (Cc) rather than P4mm tetragonal symmetry. Through local switching-spectroscopy measurements and piezoresponse force microsc...

Understanding ferroelectricity at the deep submicron regime is desirable in utilizing it for next generation nonvolatile memory devices, medical imaging systems, and rf filters. Here we show how piezoresponse force microscopy can be enhanced 1 nm resolution . Using this method, we have investigated ferroelectric and ferroelastic domains at the deep submicron regime in polycrystalline lead zirco...

We demonstrate the dramatic effect of film thickness on the ferroelectric phase transition temperature Tc in strained BaTiO3 films grown on SrTiO3 substrates. Using variable-temperature ultraviolet Raman spectroscopy enables measuring Tc in films as thin as 1.6 nm, and a film thickness variation from 1.6 to 10 nm leads to Tc tuning from 70 to about 925 K. Raman data are consistent with synchrot...