Sinan Dursun

Processing and properties of textured potassium strontium niobate (KSr 2 Nb 5 O 15 ) ceramic fibers-effect of texture on the electrical properties

Textured ceramic fibers were fabricated from the tungsten-bronze-type piezoelectric (KSr₂Nb₅O₁₅) . Development of crystallographic texture was evaluated through rocking curve analysis and a texture with Lotgering factor of 0.97 was achieved. 1-3 piezocomposites were prepared from the textured fibers and their electrical properties were evaluated. Highly enhanced properties that are 2 to 3 times higher than the random case were observed with increasing texture fraction with P_r and d₃₃ reaching 20 μC/cm² and 75 pC/N, respectively.

Processing, Structural and Electrical Properties of Textured Potassium Strontium Niobate (Ksr 2 Nb 5 O 15 ) Piezoceramic Fibers

Highly [00 textured KSr2Nb5O15 (KSN) ceramic fibers were fabricated by a combination of novel alginate gelation method and templated grain growth using acicular KSr2Nb5O15 template particles. Fibers were drawn from alginate based slurries without or with 25 and 100wt% KSN template particles. A texture fraction of 0.90 was obtained in the case of 25 wt% and a single crystal like texture was obtained in the case of 100wt%. Piezocomposites with 1-3 connectivity were prepared from the KSN fibers and their electrical and electromechanical properties were investigated. Dielectric constant of 140, piezoelectric charge coefficient of 45 pC/N, remnant polarization of 16.6 μC/cm2 and electric field induced strain of up to 0.035% were obtained from piezocomposites with textured fibers.

Macro and Microstructural Engineering of Piezoelectric Ceramics

Dimension, shape and materials’ properties are the most basic characteristics of a piezoelectric ceramic transducer determining the device performance. In our studies better electromechanical performance was obtained from piezoelectric ceramic itself by creating designs based on built-in amplification mechanisms obtained through the shape and geometry of the transducer, i.e. the macroscale engineering. Piezoceramics in thin hollow shell and fiber forms were fabricated by slip casting and alginate gelation. Additionally, improving materials properties along preferred directions can be achieved through the fabrication of crystallographically textured piezoceramics, i.e. Microscale Engineering. Alginate gelation and templated grain growth was used to produce them.

Electrical Properties of 1–3 Piezocomposites Prepared from Textured KSr2Nb5O15 (KSN) Ceramic Fibers

Highly [001] textured KSr2Nb5O15 (KSN) ceramic fibers were fabricated by a combination of novel alginate gelation method and templated grain growth using acicular KSr2Nb5O15 template particles. Fibers were drawn from alginate based slurries without or with 10 wt% KSN template particles. A maximum texture fraction of 0.96 was obtained. Piezocomposites with 1–3 connectivity were prered from the KSN fibers and their electrical and electromechanical properties were investigated. Dielectric constant of 90, piezoelectric charge coefficient of 60 pC/N, remnant polarization of 10 μC/cm2 and electric field induced strain of up to 0.036% were obtained from piezocomposites with textured fibers.

Textured lead-free KSr 2 Nb 5 O 15 piezoelectric ceramics, fibers and piezocomposites — Processing and properties

Textured ceramic fibers were fabricated from the tungsten-bronze type piezoelectric KSr2Nb5O15. Development of crystallographic texture was evaluated through rocking curve analysis and a texture with Lotgering factor of 0.97 was achieved. 1-3 piezocomposites were prepared from the textured fibers and their electrical properties were evaluated. Highly enhanced properties were observed with increasing texture fraction.