Određivanje parametara kristalne rešetke La1-xSrxMnO3 Rietveldovom metodom utočnjavanja

master's thesis

• Title (english): Determination of La1-xSrxMnO3 crystal lattice parameters by Rietveld refinement
• Author: Marija Raspor
• Mentor: Jelena Macan (mentor)
• Committee member: Jelena Macan (predsjednik povjerenstva)
• Committee member: Marica Ivanković (član povjerenstva)
• Committee member: Anamarija Rogina (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada bio je odrediti parametre kristalne rešetke stroncijem dopiranih lantanovih manganita (La1-xSrxMnO3) Rietveldovom metodom utočnjavanja te usporediti uspješnost utočnjavanja korištenjem tri različita modela. Uzorci La1-xSrxMnO3 (x = 0, 0,1, 0,2, 0,3 i 0,5) pripremljeni su postupkom koprecipitacije nakon čega su karakterizirani rendgenskom difrakcijskom analizom (XRD). Eksperimentalno dobiveni podaci su utočnjavani s teorijskim Pseudo Voigt, Triple Pseudo Voigt te Thompson-Cox Pseudo Voigt modelima u softverskom paketu FullProf. Najbolje slaganje modela i eksperimentalnih podataka dobiveno je za Pseudo Voigt i Thompson-Cox Pseudo Voigt model. Triple Pseudo Voigt model dao je najlošije slaganje s eksperimentalnim podacima zbog prevelikog broja parametara koje model koristi za utočnjavanje zbog čega „zaluta“ u lokalne minimume.

Abstract (english)

The aim of this research was to determine the crystal lattice parameters of strontium doped lanthanum manganites (La1-xSrxMnO3) by the Rietveld refinement method using three different methods. The La1-xSrxMnO3 samples (x = 0, 0.1, 0.2, 0.3, 0.5) were prepared by the coprecipitation procedure, after which they were characterized by X-ray diffraction analysis (XRD). The experimentally obtained data were refined with theoretical Pseudo Voigt, Triple Pseudo Voigt and Thompson-Cox Pseudo Voigt models in the FullProf suite. The best refinement was achieved using Pseudo Voigt and Thompson-Cox Pseudo Voigt models. The Triple Pseudo Voigt model has shown the worst match with the experimental data due to the excessive number of parameters that the function uses for refinement, which makes it "stray" into the local minima.

• Keywords: koprecipitacija; rendgenska difrakcijska analiza; Rietveldova metoda utočnjavanja
• Keywords (english): coprecipitation; X-ray diffraction analysis; Rietveld refinement
• Language: croatian
• URN:NBN: urn:nbn:hr:149:112801
• Project: Number: IP-2018-01-5246; Title: Nanokompoziti s perovskitima za fotovoltaike, fotokatalizu i senzoriku; Acronym: NanoPeroPhotoSens; Leader: Andreja Gajović; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-04-06 13:05:25