1.

»Solid State reactions Occurring during the Synthesis of CaTiO3-NdAlO3 Perovskite Solid Solutions«

The X-ray powder diffraction technique was used to investigate the solid state reaction paths to the 0.7 CT- 0.3 NA perovskite solid solution. We showed that the perovskite phases CT and NA are formed prior to the solid solution. The two perovskites subsequently react to form a solid solution at temperatures above 1200oC. The reaction between CT and NA was studied using a diffusion couple, which reveald that the slower kinetics of incorporation of the Al into the forming solid solution results in the formation of an intermediate phase based on hexaluminate CaAl12O19.

COBISS.SI-ID: 18215719

2.

»Bi-Based Compounds for Glass-Free LTCC Technology«

Today's low-temperature co-fired ceramic (LTCC) materials can be grouped into three classes: glass-ceramic composites, recrystallized glasses and glass-free ceramics. Whereas the first two of these classes of materials are already in commercial production, glass-free ceramics are still in the development stage. We have investigated a glass-free LTCC material system that consist of low-and high-permittivity LTCC materials based on Bi eulytite and sillenite compounds and a ?-Bi2O3 ss with Nb2O5. All these phases meet the main requirements for LTCC.

COBISS.SI-ID: 18709287

3.

»The influence of hydrothermal-reaction parameters on the formation of chrysotile nanotubes«

X-ray diffraction and TEM were used to investigate the hydrothermal formation of chrysotile Mg3[Si2O5](OH)4 nanotubes from amorphous SiO2 and nanocrystaline Mg(OH)2. The results show that nanotubes form readily in a highly basic hydrothermal environment via the curlin of flake-like nano crystallites with a serpentine-type Mg-Si-bilayer crystal structure. The curling occurs in a helical manner, which introduces chirality into the structure of the resulting tubes. The diameter and length of the nanotubes can be controlled by varying temperature and time of hydrothermal reaction.

COBISS.SI-ID: 19442471

4.

»In situ synthesis of Ag nanoparticles in polyelectrolyte multilayers«

Self-assembled multilayer thin films, fabricated by the sequential adsorption of appositively charged polyelectrolytes, were uased as a template for the in situ nucleation and growth of silver nanoparticles. Free acid groups in the polyelectrolyte multilayer film were used to bind the silver ions. TEM examination and UV-vis spectroscopy showed that the concentration and size of the Ag nanoparticles are determined by the processing conditions of the multilayer assembly. After 3 reaction cycles Ag nanoparticles with an average diameter of 7 nm at a volume fraction of 65% were obtained.

COBISS.SI-ID: 20902951

5.

»Phase relations and electrical properties in the pseudo-ternary La2O3-TiO2-Mn2O3 system in air«

The subsolidus phase relations in the La2O3–TiO2–Mn2O3 system in air at 1275 ?C were determined. The addition of a small amount of LaMnO3 to La2O3:3TiO2 resulted in the stabilization of a perovskite La2/3TiO3 compound with the formula La(2+x)/3Ti1-xMnxO3. Two new compounds were identified: La1.7Ti13.0Mn6.3O38-x, with a davidite-like crystal structure, and La49Ti18Mn13O129. The highest room-temperature permittivity (? = 73.7) was exhibited by the nearly single-phase La2/3TiO3-based ceramic, with a temperature coefficient ?f =-55 ppm/?C and a dielectric loss tan ?=37×10-4, at 1 MHz.

COBISS.SI-ID: 21909031