DEVELOPMENT OF POLYMER MATRIX COMPOSITES WITH TUNABLE DIELECTRIC PROPERTIES

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2022-2-08
Özkaragöz, Nadire Nazlı
Ferroelectric materials are used in different applications because of their superior electrical and dielectric properties. Ferroelectric materials are polarized when an electrical field is applied to the material. This spontaneous polarization continues even if an electrical field is removed. BST (Barium Strontium Titanate) is one of the attractive ferroelectric materials which has a high dielectric constant and low dielectric loss tangent (tanδ). High dielectric constant and low loss tangent are necessary for tunable microwave applications, particularly at X/C band frequencies. Nevertheless, monolithic BST ceramic is not a proper material for electronic applications especially when conformality is required. To eliminate this deficiency of the BST ceramics, BST particle containing polymer matrix composites (BST/PS) providing unique properties can be developed. In the current study, effect of different parameters on the characteristics and tunability performance of the dielectric properties of the BST particle containing polymer matrix composites has been investigated. BST particle size, particle size distribution and content in the composites have been determined to be the key parameters effective on the tunability potential of such composites. Within the scope of this study, it was concluded that tunability potential of the BST/PS composites improves with increasing content of the fine-sized BST ceramics having Ba/Sr/Ti molar ratio of 0.7/0.3/1 which increases further at higher applied bias voltage.

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Citation Formats
N. N. Özkaragöz, “DEVELOPMENT OF POLYMER MATRIX COMPOSITES WITH TUNABLE DIELECTRIC PROPERTIES,” M.S. - Master of Science, Middle East Technical University, 2022.