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Title: An integrated study of thermal treatment effects on the microstructure and magnetic properties of Zn-ferrite nanoparticles

Abstract

The evolution of the magnetic state, crystal structure and microstructure parameters of nanocrystalline zinc–ferrite, tuned by thermal annealing of ~4 nm nanoparticles, was systematically studied by complementary characterization methods. Structural analysis of neutron and synchrotron x-ray radiation data revealed a mixed cation distribution in the nanoparticle samples, with the degree of inversion systematically decreasing from 0.25 in an as-prepared nanocrystalline sample to a non-inverted spinel structure with a normal cation distribution in the bulk counterpart. The results of DC magnetization and Mossbauer spectroscopy experiments indicated a superparamagnetic relaxation in ~4 nm nanoparticles, albeit with different freezing temperatures T f of 27.5 K and 46 K, respectively. The quadrupole splitting parameter decreases with the annealing temperature due to cation redistribution between the tetrahedral and octahedral sites of the spinel structure and the associated defects. DC magnetization measurements indicated the existence of significant interparticle interactions among nanoparticles (‘superspins’). Additional confirmation for the presence of interparticle interactions was found from the fit of the T f(H) dependence to the AT line, from which a value of the anisotropy constant of K eff = 5.6 × 10 5 erg cm -3 was deduced. Further evidence for strong interparticle interactions was found from AC susceptibilitymore » measurements, where the frequency dependence of the freezing temperature T f(ƒ) was satisfactory described by both Vogel–Fulcher and dynamic scaling theory, both applicable for interacting systems. The parameters obtained from these fits suggest collective freezing of magnetic moments at T f .« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [2];  [3]
  1. Univ. of Belgrade (Serbia)
  2. Univ. of Paris (France)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE
OSTI Identifier:
1222035
DOE Contract Number:  
AC52-06NA25396
Resource Type:
Journal Article
Journal Name:
J. Phys. Condens. Matter
Additional Journal Information:
Journal Volume: 25; Journal Issue: 8
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Antic, Bratislav, Perovic, Marija, Kremenovic, Aleksandar, Blanusa, Jovan, Spasojevic, Vojislav, Vulic, Predrag, Bessais, Lotfi, and Bozin, Emil S. An integrated study of thermal treatment effects on the microstructure and magnetic properties of Zn-ferrite nanoparticles. United States: N. p., 2015. Web. doi:10.1088/0953-8984/25/8/086001.
Antic, Bratislav, Perovic, Marija, Kremenovic, Aleksandar, Blanusa, Jovan, Spasojevic, Vojislav, Vulic, Predrag, Bessais, Lotfi, & Bozin, Emil S. An integrated study of thermal treatment effects on the microstructure and magnetic properties of Zn-ferrite nanoparticles. United States. doi:10.1088/0953-8984/25/8/086001.
Antic, Bratislav, Perovic, Marija, Kremenovic, Aleksandar, Blanusa, Jovan, Spasojevic, Vojislav, Vulic, Predrag, Bessais, Lotfi, and Bozin, Emil S. Wed . "An integrated study of thermal treatment effects on the microstructure and magnetic properties of Zn-ferrite nanoparticles". United States. doi:10.1088/0953-8984/25/8/086001.
@article{osti_1222035,
title = {An integrated study of thermal treatment effects on the microstructure and magnetic properties of Zn-ferrite nanoparticles},
author = {Antic, Bratislav and Perovic, Marija and Kremenovic, Aleksandar and Blanusa, Jovan and Spasojevic, Vojislav and Vulic, Predrag and Bessais, Lotfi and Bozin, Emil S},
abstractNote = {The evolution of the magnetic state, crystal structure and microstructure parameters of nanocrystalline zinc–ferrite, tuned by thermal annealing of ~4 nm nanoparticles, was systematically studied by complementary characterization methods. Structural analysis of neutron and synchrotron x-ray radiation data revealed a mixed cation distribution in the nanoparticle samples, with the degree of inversion systematically decreasing from 0.25 in an as-prepared nanocrystalline sample to a non-inverted spinel structure with a normal cation distribution in the bulk counterpart. The results of DC magnetization and Mossbauer spectroscopy experiments indicated a superparamagnetic relaxation in ~4 nm nanoparticles, albeit with different freezing temperatures Tf of 27.5 K and 46 K, respectively. The quadrupole splitting parameter decreases with the annealing temperature due to cation redistribution between the tetrahedral and octahedral sites of the spinel structure and the associated defects. DC magnetization measurements indicated the existence of significant interparticle interactions among nanoparticles (‘superspins’). Additional confirmation for the presence of interparticle interactions was found from the fit of the Tf(H) dependence to the AT line, from which a value of the anisotropy constant of Keff = 5.6 × 105 erg cm-3 was deduced. Further evidence for strong interparticle interactions was found from AC susceptibility measurements, where the frequency dependence of the freezing temperature Tf(ƒ) was satisfactory described by both Vogel–Fulcher and dynamic scaling theory, both applicable for interacting systems. The parameters obtained from these fits suggest collective freezing of magnetic moments at Tf .},
doi = {10.1088/0953-8984/25/8/086001},
journal = {J. Phys. Condens. Matter},
number = 8,
volume = 25,
place = {United States},
year = {2015},
month = {9}
}