Sinteza in strukturna karakterizacija galij-stroncijevega titanata(IV)

Vodlan, Katja (author), Golobič, Amalija (mentor)

Med keramiko uvrščamo anorganske materiale, ki niso kovine ali zlitine ter jih pripravimo z žganjem pri visoki temperaturi. Keramični materiali imajo raznovrstne strukture. Osnovni strukturni podatki, ki jih moramo določiti, če želimo opisati zgradbo kristala so parametri osnovne celice, vrsta in koordinate atomov v asimetrični enoti ter prostorska skupina. Pogosto se določi tudi parametre odmika atomov, včasih pa se mora preučiti tudi zasedenost njihovih leg. Pri določevanju strukture si lahko pomagamo tudi s strukturnimi modeli. V okviru diplomskega dela smo s pomočjo predhodnih meritev na osnovi pred leti pripravljenega produkta, izvedli okvirno strukturno karakterizacijo galij-stroncijevega titanata(IV). Kvalitativno rentgensko praškovno analizo na osnovi izmerjenega praškovnega difraktograma smo opravili z računalniškim programom Crystallographica Search Match-CSM. S programom ICSD-Desktop smo v podatkovni zbirki kristalnih struktur ICSD poiskali strukturne podatke za reaktante, ki so bili uporabljeni pri sintezi produkta, in za aluminij-stroncijev titanat(IV), ki je služil kot strukturni model. S programom TOPAS 2.1 smo izvedli Rietveldovo prilagajanje, s pomočjo katerega smo izračunali masni delež kristalnih faz v kristaliničnem vzorcu in določili približno kristalno strukturo galij-stroncijevega titanata(IV), ki smo jo narisali s programom Mercury. V okviru diplomskega dela smo potrdili, da je struktura aluminij-stroncijevega titanata(IV) primeren strukturni model za določitev kristalne strukture galij-stroncijevega titanata(IV). Struktura produkta ima tako kot strukturni model monoklinsko prostorsko skupino C2/c in zelo podobno, vendar nekoliko večjo osnovno celico, kar je v skladu s tem, da imajo galijevi(3+) ioni nekoliko večji ionski radij od aluminijevih(3+).

• Language: Slovenian
• Keywords: galij-stroncijev titanat(IV), rentgenska praškovna difrakcija, EDS analiza, kvalitativna praškovna analiza
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-119664
• COBISS.SI-ID: 30804739
• Publication date in RUL: 10.09.2020

VODLAN, Katja, 2020, Sinteza in strukturna karakterizacija galij-stroncijevega titanata(IV) [online]. Bachelor’s thesis. [Accessed 17 May 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=119664

Secondary language

• Language: English
• Title: Synthesis and structural characterization of gallium strontium titanate(IV)

Abstract

Ceramics include inorganic materials that are not metals or alloys and they are synthesized by heating at high temperature. Ceramic materials have a variety of different structures. The basic structural data that we need to determine if we want to describe the structure of a crystal are the unit cell parameters, the type and coordinates of the atoms in the asymmetric unit, and the space group. The displacement parameters of the atoms may be determined and sometimes also their positions occupancy. Structural models can also be used to determine the structure of the product. As part of this work, we performed approximate structural characterization of gallium- strontium titanate (IV), with the application of the preliminary measurements, based on the the years ago prepared product. Qualitative X-ray powder analysis, based on the measured powder diffractogram, was performed with the computer program Crystallographica Search Match-CSM. Using the ICSD-Desktop program, we searched through the ICSD crystal structure database for the structural data of the reactants used in the product synthesis and for aluminum-strontium titanate (IV), which served as a structural model. Using the TOPAS 2.1 program, we performed the Rietveld-refinement, which was used to calculate the mass fraction of the crystalline phases in the crystalline part of the sample and to determine the approximate crystal structure of gallium-strontium titanate (IV), drawn with the Mercury program. As part of this work, we confirmed that the structure of aluminum-strontium titanate (IV) is a suitable structural model for determining the crystal structure of gallium-strontium titanate (IV). The structure of the product, like the structural model, shows a monoclinic space group C2 / c and a very similar, however slightly larger unit cell, which is consistent with the slightly larger gallium(III) ionic radius than for aluminum(III).

• Keywords: gallium-strontium titanate(IV), X-ray powder diffraction, EDS analysis, qualitative powder analysis