KRÁL, M. Fyzikální a elektrické vlastnosti 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 keramik [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2015.
The research conducted by Michael Kral in the area of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics has significant importance in the search for new functional piezoelectric materials. Through the whole time of the project the student worked independently and learned the complete fabrication process and methods for piezoelectric ceramics and also gained a basic knowledge of piezoelectric characterisation. The student has approached the project with good background knowledge together with strong hands-on skills. The thesis is well structured and written in English and is comparable to a level produced at British universities. The literature review is well structured and gives an overview of background knowledge and is well linked and up to date with reference to recently published research. Also the student was very proactive during the whole time of the project which resulted in a contribution to a joint paper and oral presentation at the IEEE International Symposium on Applications of Ferroelectrics, in Singapore in May 2015. The publication is attached in the appendix of the bachelor thesis. I feel that the student achieved work of excellent standard for his bachelor work and I would evaluate this work to ‘A’ mark level. Questions for student: What is a perovskite structure? What is the significance of a Morphotropic Phase Boundary for commercial piezoelectric compositions?
| Kritérium | Známka | Body | Slovní hodnocení |
|---|---|---|---|
| Splnění požadavků a cílů zadání | A | ||
| Postup a rozsah řešení, adekvátnost použitých metod | A | ||
| Vlastní přínos a originalita | A | ||
| Schopnost interpretovat dosažené vysledky a vyvozovat z nich závěry | A | ||
| Využitelnost výsledků v praxi nebo teorii | A | ||
| Logické uspořádání práce a formální náležitosti | B | ||
| Grafická, stylistická úprava a pravopis | B | ||
| Práce s literaturou včetně citací | A | ||
| Samostatnost studenta při zpracování tématu | A |
This bachelor thesis contains a search of the area of lead-free piezoceramic materials. The material based on the composition 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 by conventional solid state route is investigated. The work includes the preparation and measurements of properties of the material. In the thesis, 6 tables and 35 figures are applied to explain the piezoelectric materials in detail. In the review, it is clearly elaborated that the definition and the history of piezoelectric material, parameters used to describe piezoelectricity, and lead-based and lead-free material. The experiments are designed and completed in a scientific and logical way. The potential mistakes in the thesis are as followed: small faults of English grammar, description of contents, insufficient description of the professional words when appearing the first time, some mistakes about the description of tables and figures. Content: Though there is still a small amount of mistakes in the thesis, Michael Král’s work is excellent and it is enough to attain a bachelor’s degree. I recommend the work submitted for defence and appreciate it with total marks as A.
| Kritérium | Známka | Body | Slovní hodnocení |
|---|---|---|---|
| Splnění požadavků a cílů zadání | A | ||
| Postup a rozsah řešení, adekvátnost použitých metod | A | ||
| Vlastní přínos a originalita | A | ||
| Schopnost interpretovat dosaž. vysledky a vyvozovat z nich závěry | B | ||
| Využitelnost výsledků v praxi nebo teorii | A | ||
| Logické uspořádání práce a formální náležitosti | A | ||
| Grafická, stylistická úprava a pravopis | B | ||
| Práce s literaturou včetně citací | A |
eVSKP id 86950