How to Make Porous Piezoelectrics? Review on Processing Strategies.

Ferroelectric ceramics are a technologically important class of materials that are currently exploited in actuators, sensors, transducers, and memory devices. The introduction of porosity into these materials has been proved to be an effective tool for tuning functional properties for specific applications, such as piezoelectric and pyroelectric devices and energy harvesters. In this review, a comprehensive description of the most widely used processing techniques able to produce porous ferroelectric ceramics is reported.

A Glance at Processing-Microstructure-Property Relationships for Magnetoelectric Particulate PZT-CFO Composites.

In this work, we investigated the processing-microstructure-property relationships for magnetoelectric (ME) particulate composites consisting of hard ferromagnetic CoFeO (CFO) particles dispersed in a Nb-doped PbZrTiO (PZT) soft ferroelectric matrix. Several preparation steps, namely PZT powder calcination, PZT-CFO mixture milling and composite sintering were tailored and a range of microstructures was obtained. These included open and closed porosities up to full densification, PZT matrices with decreasing grain size across the submicron range down to the nanoscale and well dispersed CFO particles with bimodal size distributions consisting of submicron and micron sized components with varying weights.

Lead-Free BNT-BT/CoFeO Core-Shell Nanostructures with Potential Multifunctional Applications.

Herein we report on novel multiferroic core-shell nanostructures of cobalt ferrite (CoFeO)-bismuth, sodium titanate doped with barium titanate (BNT-BT), prepared by a two-step wet chemical procedure, using the sol-gel technique. The fraction of CoFeO was varied from 1:0.5 to 1:1.

Damage from Coexistence of Ferroelectric and Antiferroelectric Domains and Clustering of O Vacancies in PZT: An Elastic and Raman Study.

It is often suggested that oxygen vacancies (V O ) are involved in fatigue and pinning of domain walls in ferroelectric (FE) materials, but generally without definite evidence or models. Here the progress of damage induced by the coexistence of FE and antiferroelectric (AFE) domains in the absence of electric cycling is probed by monitoring the Young's modulus, which may undergo more than fourfold softenings without significant changes in the Raman spectra, but may end with the disaggregation of PZT with ∼5% Ti. At these compositions, the FE and AFE phases coexist at room temperature, as also observed with micro-Raman, and hence the observations are interpreted in terms of the aggregation of V O at the interfaces between FE and AFE domains, which are sources of internal electric and stress fields.

Probing the dielectric, piezoelectric and magnetic behavior of CoFeO/BNT-BT composite thin film fabricated by sol-gel and spin-coating methods.

We investigated in this paper a novel bilayer composite obtained by sol-gel and spin coating of the ferroelectric 0.92NaBiTiO-0.08BaTiO (abbreviated as BNT-BT) and ferromagnetic CoFeO phases, for miniature low-frequency magnetic sensors and piezoelectric sensors.

Combined use of Mössbauer spectroscopy, XPS, HRTEM, dielectric and anelastic spectroscopy for estimating incipient phase separation in lead titanate-based multiferroics.

The formation of separate phases in crystalline materials is promoted by doping with elements with different valences and ionic radii. Control of the formation of separate phases in multiferroics is extremely important for their magnetic, ferroelectric and elastic properties, which are relevant for multifunctional applications. The ordering of dopants and incipient phase separation were studied in lead titanate-based multiferroics with the formula (Pb0.

Encapsulation of Piezoelectric Transducers for Sensory Augmentation and Substitution with Wearable Haptic Devices.

The integration of polymeric actuators in haptic displays is widespread nowadays, especially in virtual reality and rehabilitation applications. However, we are still far from optimizing the transducer ability in conveying sensory information. Here, we present a vibrotactile actuator characterized by a piezoelectric disk embedded in a polydimethylsiloxane (PDMS) shell.

Field-induced phase transition and relaxor character in submicrometer-structured lead-free (Bi0.5Na0.5)0.94Ba0.06TiO3 piezoceramics at the morphotropic phase boundary.

Submicrometer-structured (Bi(0.5)Na(0.5))(0.

Nano-sized ceramic inks for drop-on-demand ink-jet printing in quadrichromy.

Nano-sized ceramic inks suitable for ink-jet printing have been developed for the four-colours CMYK (cyan, magenta, yellow, black) process. Nano-inks of different pigment composition (Co(1-x)O, Au(0), Ti(1-x-y)Sb(x)Cr(y)O2, CoFe2O4) have been prepared with various solid loadings and their chemicophysical properties (particle size, viscosity, surface tension, zeta-potential) were tailored for the ink-jet application. The pigment particle size is in the 20-80 nm range.