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Synthesis and characterization of different glass and glass-ceramics families (oxydes, phosphates and fluorides) with magnetic properties

Grant number: 19/19609-1
Support type:Scholarships in Brazil - Post-Doctorate
Effective date (Start): November 01, 2019
Effective date (End): October 31, 2021
Field of knowledge:Physical Sciences and Mathematics - Chemistry
Principal Investigator:Marcelo Nalin
Grantee:Juliane Resges Orives
Home Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
Associated research grant:13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass, AP.CEPID

Abstract

Two different approaches have been used in the last years to prepare magnetic glasses and glass-ceramics: A) magnetic glasses - strong paramagnetic effects can be achieve by introducing high amouts of transition metals, such as Mn, Fe and Ni, as well, as rare earths, like Gd and Tb ions into glass matrix. Such materials can be used in several kinds of photonic applications such as materials for studies in ultrafast magnetism, Faraday rotators and optical fiber sensors for geological activity. The challenger is to obtain stable enough glasses able to be transformed in optical fibers and showing both high refractive index and Verdet constant. To achieve such goal, new glass compositions must be design; B) magnetic glassceramics - in order to obtain magnetic glassceramics it is possible to crystallize a given glass composition containing unstable enough phases which may generates ferromagnetic crystal phases dispersed into the glass matrix. However, the choice of the glass matrix is not trivial and the crystallization behavior must be studied in order to obtain homogeneous crystallization. However, other approaches can be used in order to introduce magnetic nanoparticles inside the glasses. One of them is to prepare, separately, the desired nanoparticles protected by a shell of SiO2, for example, and subsequently to disperse such particles into a glassy matrix avoiding the dissolution of the magnetic nanoparticle by controlling the composition and also the time and temperature of melting. Such approach allows to obtain glassceramics (or composites) with very interesting magneto-optical properties. (AU)