Transition metal oxide nanocrystals and their interaction with light or with an alternating magnetic field

Abstract

Magnetic nanoparticles, especially those of transition metal oxides, with a crystalline ionic configuration of metal cations with unfilled d-electron orbitals, have become key in emerging fields. Through detailed analysis and characterisation, we aim to explore new possibilities for their applications. Accordingly, the following project focuses on magnetic nanocrystals (transition metal oxides) and their optimization and functionalization in order to prove them to be interesting candidates for the implementation in various field, such as heat delivery, spintronics/magnonics or bio-related applications when functionalized or interacting with biomolecules. Objectives:

• Preparation of magnetic nanostructures of transition metal oxides using chemical synthesis and novel syntheses focused on composition, crystalline structure and shape. • The assembly of nanocrystals (interface of two different magnetic nanoparticles, nanoparticles in proteins, nanoparticles in polymer films) and research of magnetic properties stemming from their functionalization and unique arrangements. • Establish magnetic nanocrystals as versatile candidates for emerging technologies heat delivery, spintronics/magnonics, and bio-related applications through detailed analysis.

Methodology: • Chemical synthesis of the nanomaterials including the methods of coprecipitation and thermal decomposition • X-Ray diffraction for the structural analysis of the synthesised nanomaterials • Raman spectroscopy for the determination of chemical and vibrational structure of the synthesised nanomaterials • Transmission Electron Microscopy, Scanning Electron Microscopy, High Resolution Electron Microscopy pictures for size and shape analysis of the synthesised nanomaterials • Ultrasound sonication for the synthesis of protein microcapsules endowed with magnetic nanocrystals and magnetosomes • VSM Magnetic measurements for the investigation of magnetic properties

Work plan: 1. Basic chemical synthesis of the nanomaterials including coprecipitation reactions, thermal decomposition in organic media and their modification in order to obtain desired shape and composition of the nanomaterials. 2. Characterisation of the synthesised nanomaterials with X-Ray Diffraction techniques for providing the information about the crystallographic structure, Raman spectroscopy for revealing the vibrational structures and corresponding modes expected in particular space symmetry group of the materials, Transmission Electron Microscopy pictures for the analysis of the size distribution with Gaussian or Log-Normal fitting and shape indication of the nanoparticles. 3. Magnetic measurements providing the information about magnetic behaviour by analysing the data of magnetisation versus field strength, magnetisation versus temperature and analysis of various effects: reduced size effect (Cr2O3), exchange bias phenomena (Cr2O3-Fe3O4) and correlation (Fe3O4, Mn2O4, CoFe2O4) with heat generation registered in magnetic hyperthermia. 4. Synthesis of BSA protein microcapsules endowed with magnetic nanocrystals and magnetosomes by ultrasound chemistry method and heat delivery, magnetic manipulation studies, Scanning Electron Microscopy, and Transmission Electron Microscopy for the detailed analysis of hybrid microcapsules and biomedical application. 5. Fabrication of PVA films with Cr2O3 nanocrystals by electrospinning method for the studies of spin-phonon coupling effect and detailed Raman spectroscopy analysis for the analysis spin-phonon coupling. 6. Fabrication and analysis of microsponges with Fe3O4 magnetic nanocrystals with various shapes (spherical, octahedral) for biomedical application. 7. Discussion and conclusion on the performed research and proposals for the future investigation.

Las nanopartículas magnéticas, especialmente aquellas de óxidos de metales de transición, con una configuración iónica cristalina de cationes metálicos con orbitales de electrones d vacíos, se han vuelto clave en campos emergentes. A través de un análisis y una caracterización detallados, nuestro objetivo es explorar nuevas posibilidades para sus aplicaciones. En consecuencia, el siguiente proyecto se centra en nanocristales magnéticos (óxidos de metales de transición) y su optimización y funcionalización con el fin de demostrar que son candidatos interesantes para la implementación en diversos campos, como el suministro de calor, la espintrónica/magnónica o aplicaciones biorelacionadas cuando están funcionalizados o interactuar con biomoléculas.

As nanopartículas magnéticas, especialmente as dos óxidos de metais de transición, cunha configuración iónica cristalina de catións metálicos con orbitais de electróns d sen cheos, convertéronse en clave nos campos emerxentes. Mediante unha análise e caracterización detalladas, pretendemos explorar novas posibilidades para as súas aplicacións. En consecuencia, o seguinte proxecto céntrase nos nanocristais magnéticos (óxidos de metais de transición) e a súa optimización e funcionalización co fin de demostrar que son candidatos interesantes para a súa implementación en diversos campos, como a entrega de calor, a espintrónica/magnónica ou as aplicacións bio-relacionadas cando se funcionalizan ou interactuando con biomoléculas.