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Nanoparticles based on 3d metal oxides - correlation of structure and magnetism
Kubíčková, Simona ; Kalbáčová Vejpravová, Jana (advisor) ; Cannas, Carla (referee) ; Svoboda, Pavel (referee)
Title: Nanoparticles based on 3d metal oxides - correlation of structure and magnetism Author: RNDr. Simona Kubíčková Department: Institute of Physics CAS, v.v.i. Supervisor: doc. RNDr. Jana Kalbáčová Vejpravová, Ph.D., Institute of Physics CAS, v.v.i. Abstract: The thesis is focused on the correlation of the magnetic response of iron oxide nanoparticles (NPs) with their internal structure. Several complementary methods were used and compared that bring insight into the relative crystallinity of the investigated NPs. The main goal was devoted to the elucidation of the origin of the so-called spin canting angle determined by In-field Mössbauer Spectroscopy (IFMS) by examination of samples with different internal structure. It has been observed that the IFMS is not an unambiguous method to study the surface effects in the NPs as the IFMS is sensitive only to the average value of all spins and does not distinguish between the surface and core effects. Moreover, the IFMS was performed on the epsilon phase of the iron(III) oxide NPs in order to inspect the peculiar behavior of this phase in an external magnetic field. Keywords: iron oxide nanoparticles, magnetism, In-field Mössbauer Spectroscopy, spin canting
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Nanoparticles based on 3d metal oxides - correlation of structure and magnetism
Kubíčková, Simona ; Kalbáčová Vejpravová, Jana (advisor) ; Cannas, Carla (referee) ; Svoboda, Pavel (referee)
Title: Nanoparticles based on 3d metal oxides - correlation of structure and magnetism Author: RNDr. Simona Kubíčková Department: Institute of Physics CAS, v.v.i. Supervisor: doc. RNDr. Jana Kalbáčová Vejpravová, Ph.D., Institute of Physics CAS, v.v.i. Abstract: The thesis is focused on the correlation of the magnetic response of iron oxide nanoparticles (NPs) with their internal structure. Several complementary methods were used and compared that bring insight into the relative crystallinity of the investigated NPs. The main goal was devoted to the elucidation of the origin of the so-called spin canting angle determined by In-field Mössbauer Spectroscopy (IFMS) by examination of samples with different internal structure. It has been observed that the IFMS is not an unambiguous method to study the surface effects in the NPs as the IFMS is sensitive only to the average value of all spins and does not distinguish between the surface and core effects. Moreover, the IFMS was performed on the epsilon phase of the iron(III) oxide NPs in order to inspect the peculiar behavior of this phase in an external magnetic field. Keywords: iron oxide nanoparticles, magnetism, In-field Mössbauer Spectroscopy, spin canting
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