Search Results (30)
Development of silicon carbide based implants with improved biocompatibility and mechanical properties
With emerging need for orthopaedic implants and prolonged exposure of organism to implants also problems connected to elution of metal ions that in some cases cause adverse reactions in the human body, emerge. The main aim of our work was therefore to investigate the potential of silicon carbide (SiC) to …
A New Synthesis Route to Pb(Mg1/3Nb2/3)O3-Based Materials by the Controlled Agglomeration of Reagent Particles
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 …
Giant energy-conversion effects in soft and solid advanced materials
This thesis presents the results of our experimental work in the field of new advanced materials such as liquid crystal elastomers (LCEs), electrocalorics and magnetoelectrics. In the first part, the conversion of thermal to mechanical energy is addressed in LCEs. The three important, newly discovered, chemical and physical parameters for …
Innovative electroconductive ceramic composites based on Si3N4
This thesis describes an investigation of electrically conductive composites based on Si3N4 with dispersed TiN or ZrN particles fabricated by an in-situ composite method. The influence of the amount of conductive phase of the Si3N4/TiN and Si3N4/ZrN composites on the density, the flexural strength and the electrical conductivity were evaluated. …
The synthesis and characterization of glass–ceramics based on ternary system MgO-B2O3-SiO2
The past fifteen years has seen the rapid development of various wireless communication devices, which operate at microwave or milimeterwave frequencies (mobile phones, wireless local-area networks (LAN), Bluetooth, etc.). At the same time, this progress has stimulated the development of new materials and process technologies, which enable the size reduction …
Structural and electrical properties of 0.65PMN-0.35PT thick films on different substrates
A starting powder with the nominal composition 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 (0.65PMN–0.35PT), which corresponds to the morphotropic phase boundary (MPB) composition, was prepared by mechanochemical activation followed by attritor milling and low-temperature calcination at 700°C. It had a narrow particle size distribution with the median particle size equal to 0.3 μm. From the …
The hydrolysis of AlN powder and its use for the synthesys of nanostructured alumina coatings
he thesis describes a study of aluminum nitride (AlN) powder hydrolysis in the temperature range between 5 °C and 90 °C. The analysis of the temperature dependence of the course of the hydrolysis and the reaction kinetics, along with a mechanistic model set up for the hydrolysis reactions, gives a …
Polyelectrolyte multilayer template assisted in-situ synthesis of inorganic nanostructures
Thin film nanocomposites consisting of inorganic matter embedded within a soft polymeric matrix on the nanometer scale have attracted much interest lately due to their unique properties with potential application in optoelectronics and photonics. Polyelectrolyte multilayers formed by the layer-by-layer electrostatic assembly of oppositively charged polyions can be utilized as …
The synthesis and characterization of BaO-rich phases within the BaO-Nb2O5 and BaO-WO3-Nb2O5 systems
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 …
High-alumina porcelain with improved mechanical and thermal properties
The study presents the influence of increasing the amount of β-spodumene (LiAlSi2O6) as Li2O-content flux on phase composition, microstructural evolution and physical properties of high alumina porcelain material containing ~61% of Al2O3. New porcelain compositions based on clays and high amount of calcined alumina were developed with the introduction of …