Linear and nonlinear optical properties of ferrofluids: nanoparticle's size effect

• Grant number: 13/13384-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2013
• End date: February 28, 2015
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Antonio Martins Figueiredo Neto
• Grantee: Eduardo Sell Gonçalves
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/13616-4 - Optical and structural properties of elastomers and complex fluids of biological interest, AP.TEM

Abstract

Ferrofluids are colloidal suspensions of magnetic nanoparticles with diameter about 10nm dispersed in a liquid carrier. Ferrofluids have applications in many areas and are commonly used as mechanical seal in hard-drives, to reduce friction when applied on the surfaces of strong magnets as well as to remove heat from speakers. Moreover, they are used in biomedicine as contrast to magnetic resonance imaging. There are also studies in cancer treatment by thermotherapy using ferrofluids, as well as in the coating of nanoparticles with biological molecules to drug delivery into a particular body region. Thus, ferrofluids with nanoparticles based on ferrites produced in Grupo de Fluidos Complexos, Universidade de Brasília, will be studied to determine the relationship between linear and non-linear optical properties and diameter of nanoparticles. Different solutions with nanoparticles of diameter between 3nm and 15nm formed of ferrites, MFe2O4 (M = Co, Cu, Ni, Zn, Mn), in particular cobalt ferrite, CoFe2O4, will be studied by means of a spectrophotometer for determining linear parameters as linear absorption and the energy gap of the nanoparticles, as well as the z-scan technique for determination of non-linear parameters, such as nonlinear absorption and nonlinear refractive index. The results will be compared with the nanoparticle size to determine the relationship between those properties and the average diameter of the particles in solution.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

GONÇALVES, Eduardo Sell. Structure, magnetic, linear and nonlinear optical properties of ferrofluids: nanoparticles size effects. 2015. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Física (IF/SBI) São Paulo.