No abstract

Articles you may be interested inPhase structure, microstructure, and electrical properties of bismuth modified potassium-sodium niobium leadfree ceramics

The synthesis of 4-methyl-2,6-di(pyrazol-1-yl)pyridine (L) and four salts of [FeL 2 Torr pressure inside the powder diffractometer causes a reversible transformation back to the high-temperature crystal phase. Consideration of thermodynamic data implies this cannot be accompanied by a low high spin state change, however. Both compounds also exhibit the LIESST effect, with 2 exhibiting an unusually high T(LIESST) of 112 K. The salts 3 and 4 are respectively high-spin and low-spin between 3-300 K, with crystalline 3 exhibiting a more pronounced version of the same Jahn-Teller distortion.3

Piezoelectric sensors and actuators are a mature technology, commonplace amongst a plethora of industrial fields including automotive, maritime and non-destructive testing. However the environments that these devices are required to serve in are becoming more demanding, with temperatures being driven higher to increase efficiencies and reduce shut-downs. Materials to survive these temperatures have been the focus of many research groups over the last decade, but there still remains no standard for the measurement of piezoelectric materials at high temperature. This is required to effectively determine comparable Figures of Merit into which devices can be successfully designed. As part of a recent European effort to establish metrological techniques for high temperature evaluation of electro-mechanical properties, we present here a review of the most promising high temperature polycrystalline materials. Where their properties allow operation above that of the ubiquitous commercial material lead zirconate titanate, as well as work done to modify a promising high temperature system, for use as a material standard.

Perovskite lithium and bismuth modified potassium-sodium niobium lead-free ceramics for high temperature applications Appl.