| Title |
Synthesis and characterization of yttrium and terbium iron perovskites and yttrium iron garnet / |
| Translation of Title |
Itrio ir terbio geležies perovskitų bei itrio geležies granato sintezė ir apibūdinimas. |
| Authors |
Januškevičius, Justinas |
| Full Text |
|
| Pages |
50 |
| Keywords [eng] |
Yttrium, Terbium, oxide, ferrite, ferrites, orthoferrite, garnet, perovskite, coating, dip coating, spin coating, thin film, silicon, nanomaterials, nanotubes, magnetic, multiferroic, YIG, YIP, TIP, Y3Fe5O12, YFeO3, TbFeO3 |
| Abstract [eng] |
Garnet and perovskite structures are among the most promising in the field of ceramics for many new or developing technologies. Yttrium iron garnet, in particular, is already well known and used for its characteristic magnetic properties. Perovskites, meanwhile, have been leading improvements in a variety of fields – photovoltaics, catalysis, sensors, superconductivity and – more recently – have shown promise in the resurgent field of multiferroics. Creating new technologies like that is especially important, because some that are used today are nearing theoretical limits in regards to what can be improved. Because of this, large efforts are being made in order to find new compounds with useful properties that could enable this innovation, and also to find simple but potent synthesis routes that would allow to create desired structures from these materials, as that can heavily impact both their properties and applicability. Current work attempts to delve into this area. The three compounds investigated – garnet Y3Fe5O12 and perovskites YFeO3 and TbFeO3 are either already used or show promise for their magnetic properties. In this work, it is shown that a simple aqueous sol-gel route using inorganic salt precursors is capable of producing pure powders of these materials, and that it can also be adapted -with varying degrees of success- to create coatings by using dip coating or spin coating procedures, which are standard in an industrial setting. It also shows that the same sol-gel process is versatile enough that it can also be adapted, through a membrane-assisted method, to produce nanotubes that have a well-defined structure. The gel used for the production of powders is investigated by thermogravimetric method to evaluate the temperatures of the main processes occurring during heating. X-ray diffraction is used to identify phase purity of the powders, coatings and nanotubes, with some help from Mossbauer spectroscopy in some cases. Scanning electron microscopy is used to examine surfaces and thickness of dip coating samples, also nanotube size and other features. Atomic force microscopy is also employed to determine the roughness of the dip coating samples. Magnetic measurements were carried out for some of the coatings. |
| Dissertation Institution |
Vilniaus universitetas. |
| Type |
Master thesis |
| Language |
English |
| Publication date |
2020 |
