Ferroelektrik KSr2Nb5O15 seramiklerinde şablon parçacıklar kullanılarak doku oluşturulması

Abstract

Concerning a certain property, some materials show different coefiBcj different crystallographic directions, this is called anisotropy. It can be given as a simple example that it is harder to cut a piece of wood perpendicular to its length than to cut it parallel to length. For some materials a similar situation is valid for electrical properties, those materials show maximum coefficients for electrical properties in a direction or set of directions. For such materials, when correctly electroded and poled a single crystal shows best electrical properties. However such disadvantages of single crystal growth as high cost, need for special conditions, limitations in dimensions and time consumption makes it difficult to use single crystal growth method especially in large scale production. An alternative to single crystal growth is the templated grain growth (TGG). TGG is based on forming crystallographic texture in polycrystalline materials using template particles. For some properties textured ferroelectric ceramics can show better properties compared to those of randomly oriented materials. In this work, ferroelectric KSraNbsOıs (KSN) ceramics with [001] textured microstructures were produced using KSN templates. Orientation of templates was carried out by tape casting method. Effects of sintering time and temperature, excess NbaOs and template content on density, microstructure and texture ratio were examined. Maximum amount of texture achieved is %98. This value is obtained by sintering the %10 template and %1.5 excess NbiOs containing sample at 1450°C for 6 hours.