The inversion degree(X)of a spinel-type nanomaterial is an essential parameter to understand the mag netic and electronic properties of ferrites.In this work,we have related different theoretical and experi mental app...The inversion degree(X)of a spinel-type nanomaterial is an essential parameter to understand the mag netic and electronic properties of ferrites.In this work,we have related different theoretical and experi mental approaches in order to know the X parameter of a Co-based spinel.Our hypothesis is that the hys teresis curve at 5 K may be used tofind the X parameter taking into consideration that the coercivity and remanence of this kind of nanoparticle(NP)are strongly dependent on the cation distribution between A and B sites of the spinel structure.To investigate this,CoFe_(2)O_(4)NPs werefirstly synthesized and fully characterized by powder X-ray diffraction(PXRD),transmission electron microscopy(TEM),and vibrating sample magnetometry(VSM).These results pointed out monodisperse CoFe_(2)O_(4)nanostructures with a spherical shape of 6.85±0.05 nm.Subsequently,first-principles calculations were carried out to obtain the most stable atomic configuration as a function of the level of inversion,as well as the atomic pro perties for each X.Then,these data were used to define the constants used in the micromagnetic calcu lations.A hysteresis loop was generated for each X and further compared to the experimental curve measured at 5 K.In this sense,the bestfit was found for X=0.75,which indicates this value as the most probable inversion degree for the CoFe_(2)O_(4)nanostructures investigated in this work.Overall,we are able to connect the experiments with the atomistic explanation through micromagnetic simulations in order tofind the cationic configuration of the Co-based spinel nanostructure.展开更多
基金support of ICM P10-061-F by Fondo de Innovación para la Competitividad-Minecon,the Basal Funding for Scientific and Technological Centers number AFB180001 CEDENNA(Conicyt)Fondecyt Projects numbers 3170240,11170544,1200782 and 1201491+2 种基金JLP acknowledges CIP2018006 from Universidad Central de ChileSEB acknowledges the support of DICYT project 041931BRthe super computing infrastructure of the NLHPC(ECM-02).
文摘The inversion degree(X)of a spinel-type nanomaterial is an essential parameter to understand the mag netic and electronic properties of ferrites.In this work,we have related different theoretical and experi mental approaches in order to know the X parameter of a Co-based spinel.Our hypothesis is that the hys teresis curve at 5 K may be used tofind the X parameter taking into consideration that the coercivity and remanence of this kind of nanoparticle(NP)are strongly dependent on the cation distribution between A and B sites of the spinel structure.To investigate this,CoFe_(2)O_(4)NPs werefirstly synthesized and fully characterized by powder X-ray diffraction(PXRD),transmission electron microscopy(TEM),and vibrating sample magnetometry(VSM).These results pointed out monodisperse CoFe_(2)O_(4)nanostructures with a spherical shape of 6.85±0.05 nm.Subsequently,first-principles calculations were carried out to obtain the most stable atomic configuration as a function of the level of inversion,as well as the atomic pro perties for each X.Then,these data were used to define the constants used in the micromagnetic calcu lations.A hysteresis loop was generated for each X and further compared to the experimental curve measured at 5 K.In this sense,the bestfit was found for X=0.75,which indicates this value as the most probable inversion degree for the CoFe_(2)O_(4)nanostructures investigated in this work.Overall,we are able to connect the experiments with the atomistic explanation through micromagnetic simulations in order tofind the cationic configuration of the Co-based spinel nanostructure.
