Construction Of Phase Boundary Research Articles

Structural, dielectric and ferroelectric properties of BiFeO3–BiInO3 solid solution thin films obtained by sol-gel method

The construction of phase boundaries is a well-known strategy to enhance the performances of ferroelectrics. In the present work, BiFeO3 and BiInO3 with attractive high Curie temperature of 830 °C and 600 °C were considered to reveal an unexplored phase boundary. (100-x)BiFeO3-xBiInO3 (x = 10, 20, 30, 40, 41, 50, 60, and 80) films, with thicknesses of approximately 289 nm, were obtained through industrial-scalable sol-gel method on Pt/Ti/SiO2/Si substrates. Complete solid solution can form between BiFeO3 and BiInO3, changing from rhombohedral to orthorhombic structure with the increase of BiInO3 content. The macroscopic dielectric, ferroelectric and piezoelectric properties of the thin films were systematically studied to understand the effect of the solid solution, with its phase diagram being proposed. A phase boundary near 60BiFeO3–40BiInO3 is formed with much superior polarization switch and piezoelectric response, of which the Curie temperature is as high as 470 °C. The results not only deepen the understanding of BiFeO3-based solid solutions, but also push forward potential applications of BiFeO3-based films in devices particularly for potential application at elevated temperature.

Potassium sodium niobate (KNN) lead-free piezoceramics: A review of phase boundary engineering based on KNN materials

<abstract> <p>Lead zirconia titanate (PZT) is the most often used piezoelectric material in various electronic applications like energy harvesters, ultrasonic capacitors and motors. It is true that PZT has a lot of significant drawbacks due to its 60% lead content, despite its outstanding ferroelectric, dielectric and piezoelectric properties which influenced by PZT's morphotropic phase boundary. The recently found potassium sodium niobate (KNN) is one of the most promising candidates for a new lead-free piezoelectric material. For the purpose of providing a resource and shedding light on the future, this paper provides a summary of the historical development of different phase boundaries in KNN materials and provides some guidance on how to achieve piezoelectric activity on par with PZT through a thorough examination and critical analysis of relevant articles by providing insight and perspective of KNN, which consists of detailed evaluation of the design, construction of phase boundaries and engineering for applications.</p> </abstract>

Piezoelectric and dielectric properties of lead-free 0.96(K0.48Na0.535)0.96Li0.04Nb1-xSbxO3-0.04CaZrO3 ceramics with rhombohedral–orthorhombic phase boundary

ABSTRACTLead-free 0.96(K0.48Na0.535)0.96Li0.04Nb(1-x)SbxO3-0.04CaZrO3 ceramics were prepared by a conventional solid-state reaction method. The crystal structure of the ceramics was found transforming from an orthorhombic phase to a rhombohedral phase with the increase of Sb content. Furthermore, a rhombohedral-orthorhombic phase boundary was determined in 0.03 ≤ x ≤ 0.05, near which the ceramics exhibited relatively high piezoelectric properties, with maximum values of d33 ∼ 213 pC/N and kp ∼ 0.37 at x = 0.03. Our results suggest that Sb may play an important role in the construction of phase boundary as well as the improvement of piezoelectric activity for (K,Na)NbO3-based piezoelectric ceramics.

Phase boundary design and high piezoelectric activity in (1−x)(Ba0.93Ca0.07)TiO3-xBa(Sn1−yHfy)O3 lead-free ceramics

The (1−x)(Ba0.93Ca0.07)TiO3-xBa(Sn1−yHfy)O3 (BCTSH-x-y) lead-free ceramics were synthesised by the conventional solid-state reaction method, and the influences of doping elements (Ca, Sn, Hf) content on their phase structure, microstructure, and electrical properties were systematically investigated. The phase boundaries concerning the orthorhombic and tetragonal (O-T) phases were found in the 0.925(Ba0.93Ca0.07)TiO3-0.075Ba(Sn1-yHfy)O3 ceramics with 0 ≤ y ≤ 0.25, and then the enhanced piezoelectric properties with d33 ∼ 550 pC N−1 were obtained. In addition, the addition of Hf can also improve the Curie temperature (TC) and ferroelectric properties of the ceramics. As a result, the electrical properties of BaTiO3 can be optimized by the construction of phase boundaries through Ca, Sn, and Hf co-doping.

An efficient method to calculate multisolid-(wax) precipitation

Based on the multisolid-wax precipitation assumption for petroleum mixtures, a monotonic equation is proposed for the calculation of liquid and multisolid equilibria. Owing to the fact that the number of precipitating species can be determined instantly at fixed temperature and pressure through a stability analysis, the computation is fast and reliable. Although the developed iteration procedure is focus to liquid mixtures it is shown that can be easily incorporate into existing vapor–liquid iteration procedures based on the Rachford–Rice equation to get a vapor–liquid–multisolid-(wax) flash calculations. Numerical experimentations are shown and even more the proposed iteration method is used in the construction of phase boundaries without any problem.