Magnetska uređenja i fenomeni u dopiranom CaMnO3 manganitu

master's thesis

• Title (english): Magnetic ordering and phenomena in doped CaMnO3 manganite
• Author: Lara Brusač
• Mentor: Nikolina Novosel (mentor)
• Committee member: Nikolina Novosel (predsjednik povjerenstva)
• Committee member: Damjan Pelc (član povjerenstva)
• Committee member: Ivan Kupčić (član povjerenstva)
• Committee member: Danko Radić (član povjerenstva)
• Committee member: Neven Žitomir Barišić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2024-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Perovskitni manganiti materijali su raznolikih svojstava ovisnih o sastavu. Promjena njihovog sastava ili veličine kristalnih zrna utječe na interakcije medu magnetskim momentima iona mangana u materijalu, što može dovesti do pojave neobičnih magnetskih fenomena. U ovom diplomskom radu proučena su i opisana magnetska svojstva dva nanokristalna uzorka kalcijevog manganita s različitim udjelima dopiranja ionima erbija. Svojstva uzoraka ispitana su AC i DC magnetometrijom te su u oba uzorka uočene... More značajke feromagnetskog i antiferomagnetskog uredenja na niskim temperaturama. Mjerenjima AC magnetometrije uočeno je staklasto ponašanje magnetskih momenata. Uzorak s većim udjelom dopiranja pokazuje i anizotropiju izmjene. U uzorcima je istovremeno prisutno više različitih magnetskih uređenja što se može objasniti modelom jezgre i ljuske s različitim magnetskim uređenjem, koji je tipičan za opis magnetskih svojstava nanomaterijala. Less

Abstract (english)

Perovskite manganites are a class of materials of diverse properties which depend on their composition. Changing the composition or crystallite size of the material impacts the interactions of the manganese ion magnetic moments, which can lead to the appearance of unusual magnetic phenomena. This diploma thesis investigates the magnetic properties of two nanocrystalline samples of calcium manganite with differing erbium ion doping concentration. Sample properties have been investigated by AC... More and DC magnetometry. Both samples show evidence of antiferromagnetic and ferromagnetic ordering at low temperatures. AC magnetometry measurement results indicate glassy behavior of the magnetic moments. The sample with higher erbium ion concentration displayed exchange bias behaviour. The samples contain coexisting regions of different magnetic ordering which can be explained by the core-shell model typically used to describe the magnetic properties of nanomaterials, which assumes that the magnetic structure of the core and the shell are different. Less

• Keywords: perovskitni manganiti; magnetizam; nanočestice
• Keywords (english): perovskite manganites; magnetism; nanoparticles
• Language: croatian
• URN:NBN: urn:nbn:hr:217:872055
• Project: Title: Ground states in competition – strong correlations, frustration and disorder
• Study programme: Title: The University Integrated Undergraduate and Graduate Programme in Physics; Research Physics; specializations in: Research Physics; Course: Research Physics; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: sveučilišni magistar fizike (sveučilišni magistar fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Public note: Ovaj rad nastao je u okviru projekta: Osnovna stanja u kompeticiji – jake korelacije, frustracija i nered.
• Created on: 2025-02-01 10:10:12