Ferroelectric materials have the ability to convert electrical energy into mechanical energy and vice versa, which makes them widely used as sensors, actuators, and ultrasonic transducers. While their electrical and electromechanical properties are well studied, mechanical properties like Young’s modulus (E) and hardness (H) remain known to a lesser extent. …
Fabrication of electroceramics usually requires high sintering temperatures of 800 to 1400 °C, which can unintentionally lead to problems such as volatilization of species, formation of secondary phases and excessive grain growth. These problems can cause inhomogeneous microstructures, non-stoichiometric chemical compositions and limited material functionality. Therefore, there is a need …
All-solid-state batteries are one of the key technologies for future energy storage and the transition to a climate-neutral society. They offer improved safety, stability, and a broader operating temperature range compared to conventional batteries with liquid electrolyte. Perovskite Li0.33La0.56 0.11TiO3 (LLTO) is recognized as one of the most promising solid …
In the scope of this thesis, I focused on SrTiO3 (ST)-based dielectric ceramic composites as a lead-free perovskite material, which holds great potential for use in various electronic components. Such materials are large-scale and fabricated under high energy requirements, indicating an increasing need for a more environmentally friendly processing method. …
The KNN solid solution was prepared from pre-synthesized binary compounds of, sodium and potassium niobate in a 1/1 molar ratio. The KNG sintering aid was prepared by homogenizing the pre-reacted binary mixtures of alkaline reagents and germanium oxide with the Na/Ge = 1/1 and K/Ge = 1/1 molar ratios. The …
KTaO3 belongs to the group of incipient ferroelectrics, which are materials important from the fundamental, as well as from the applications, point of view. It is well known in its single-crystal form; however, the processing of technologically interesting ceramics and thin films is a challenging task and knowledge of their …
In this thesis we demonstrate a new, simple, and ecient method for the solid-state synthesis of oxides with a complex chemical composition. We modify the traditional solidstate synthesis method, which is used in the majority of ceramics laboratories around the world, in order to prepare multi-metallic oxide powders from classic …
This PhD thesis presents experimental results from the synthesis, crystal structure and microwave dielectric characterization of BaO-rich phases within the BaO-Nb2O5 and BaONb2O5- WO3 system. I was primarily interested in two compounds with unknown crystal structure, i.e., the binary Ba4Nb2O9 and the ternary Ba6Nb2WO14, which lie on a common virtual …
The study of PbZrO3 (PZ), PbTiO3 (PT) and La2Zr2O7 (LZ) prepared by alkoxide sol-gel synthesis is described. PZ and PT sols were prepared from lead acetate, zirconium and titanium n-butoxide, in n-butanol and hydrolysed with Rw (molar ratio of water per lead acetate) between 2 and 15 in neutral medium …