Lead zirconate titanate

About: Lead zirconate titanate is a research topic. Over the lifetime, 7141 publications have been published within this topic receiving 150878 citations.

Effect of Poling Direction on R-Curve Behavior in Lead Zirconate Titanate

Abstract: R-curves of lead zirconate titanate (PZT) have been measured with compact tension (CT) specimens for different poling conditions and grain sizes. Depending on poling direction the plateau value of the R-curves ranged from 1.13 to 1.54 MPa·m1/2 for a grain size of 6.4 μm and from 1.14 to 1.30 MPa·m1/2 for a grain size of 5.2 μm. Poling in the thickness direction yielded the material with the highest fracture toughness while the direction parallel to the loading direction led to the lowest fracture toughness.

Electrospinning of alumina nanofibers using different precursors

Abstract: Electrospinning technique is becoming increasingly13; popular for the preparation of nanofibers [1x2013;5]. The13; process involves the application of a strong electrostatic13; field to a capillary connected with a reservoir13; containing a polymer solution or melt. Under the13; influence of the electrostatic field, a pendant droplet of13; the polymer solution at the capillary tip is deformed13; into a conical shape (Taylor cone). If the voltage surpasses13; a threshold value, electrostatic forces overcome13; the surface tension, and a fine charged jet is ejected.13; The jet moves towards a ground plate, which acts as a13; counter electrode. The solvent begins to evaporate13; immediately after the jet is formed. The result is the13; deposition of nanofibers on a substrate located above13; the counter electrode. Initially, this technique was used13; for the preparation of polymer nanofibers [6x2013;9]. In13; recent years; this technique has been used for the13; preparation of metal oxide/ceramic nanofibers such as13; silica, zirconia, titania, nickel oxide, barium titanate,13; lead zirconate titanate and other oxide materials [10x2013;13; 30]. The nanofibers formed could be aligned (parallel13; and cross patterns) when an insulated cylinder attached13; to the axel of a DC motor is used as the substrate [31].13; Xia et al. [32] prepared polymeric and ceramic nanofibers13; as axially aligned arrays by the use of a collector13; consisting of two pieces of electrically conductive13; substrate separated by a gap. Katta et al. used copper13; wires spaced evenly in the form of a circular drum as a13; collector of the electro spun nanofibers

A reusable PZT transducer for monitoring initial hydration and structural health of concrete.

Abstract: During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important for concrete suppliers. Surface bonded lead zirconate titanate (PZT) transducers have been used for damage detection and parameter identification for various engineering structures over the last two decades. In this work, a reusable PZT transducer setup for monitoring initial hydration of concrete and structural health is developed, where a piece of PZT is bonded to an enclosure with two bolts tightened inside the holes drilled in the enclosure. An impedance analyzer is used to acquire the admittance signatures of the PZT. Root mean square deviation (RMSD) is employed to associate the change in concrete strength with changes in the PZT admittance signatures. The results show that the reusable setup is able to effectively monitor the initial hydration of concrete and the structural health. It can also be detached from the concrete for future re-use.

A Nonlinear Acoustic Technique for Crack Detection in Metallic Structures

Abstract: A crack detection technique based on nonlinear acoustics is investigated in this study. Acoustic waves at a chosen frequency are generated using an actuating lead zirconate titanate (PZT) transducer, and they travel through the target structure before being received by a sensing PZT wafer. Unlike an undamaged medium, a cracked medium exhibits high acoustic nonlinearity which is manifested as harmonics in the power spectrum of the received signal. Experimental results also indicate that the harmonic components increase nonlinearly in magnitude with increasing amplitude of the input signal. The proposed technique identifies the presence of cracks by looking at the two aforementioned features: harmonics and their nonlinear relationship to the input amplitude. The effectiveness of the technique has been tested on aluminum and steel specimens. The behavior of these nonlinear features as crack propagates in the steel beam has also been studied.

Piezoelectric properties of sol‐gel‐derived ferroelectric and antiferroelectric thin layers

Abstract: The piezoelectric properties of ferroelectric and antiferroelectric thin layers were investigated by interferometry as a function of frequency and dc electric bias. Materials included: a ferroelectric lead zirconate titanate (PZT) with a Zr/Ti ratio of 53/47; a relaxor ferroelectric La‐modified PZT with a Zr/Ti ratio of 70/30 and a La content of 7.8 at. %; and antiferroelectric lead zirconate. The hysteretic behavior of the piezoelectric coefficient due to polarization reversal was also studied. The layers were prepared by a sol‐gel method, and were found to have properties similar to bulk ceramics. Significant strain levels could be achieved in the materials due to the relatively high electric strengths supported in thin‐layer form. Polarization was found to be completely switchable between forward and reverse directions; however, the strain levels generated by switching were found to be inequivalent. In addition, pronounced piezoelectric relaxations and strong piezoelectric losses were observed.