Controlled self-assembly of multiferroic core-shell nanoparticles exhibiting strong magneto-electric effects

Sreenivasulu, G.; Popov, M. A.; Chavez, Ferman A.; Hamilton, Sean L.; Lehto, Piper R.; Srinivasan, G.

doi:10.1063/1.4863690

Cited by 48 publications

(24 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such type of distribution of MF phases is given in the recent reported work. 18 Figures 1(a) and 1(b) show the possible growth mechanism for small nanoparticles of CNZF/BT and nanowires of HNZF/BT composite. In case of CNZF/BT [ Fig.…”

Section: Resultsmentioning

confidence: 99%

Multiferroic Ni0.6Zn0.4Fe2O4-BaTiO3 nanostructures: Magnetoelectric coupling, dielectric, and fluorescence

Verma

Singh

Tripathi

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

Multiferroic nanostructures of Ni0.6Zn0.4Fe2O4-BaTiO3 (NZF/BT) have been prepared by two synthesis routes, i.e., chemical combustion (CNZF/BT) and hydrothermal (HNZF/BT). The synthesis of CNZF/BT results in nanoparticles of average size 4 nm at 500 °C annealing. However, the synthesis of HNZF/BT with hydrolysis temperature 180 °C/48 h shows nanowires of diameter 3 nm and length >150 nm. A growth mechanism in the fabrication of nanoparticles and wires is given. X-ray diffraction is used to identify the crystalline phase. The transmission electron microscopy shows the dimensions of NZF/BT nanostructures. The ferromagnetism, ferroelectricity, and magnetoelectric coupling show more enhancements in HNZF/BT nanowires than CNZF/BT nanoparticles. The observed polarization depends upon shape of nanostructures, tetragonal phase, and epitaxial strain. The tension induced by the surface curvature of nanowire counteracts the near-surface depolarizing effect and meanwhile leads to unusual enhancement of polarization. The ferromagnetism depends upon superficial spin canting, spin pinning of nanocomposite, and oxygen vacancy clusters. The magnetoelectric coefficient as the function of applied dc magnetizing field under ac magnetic field 5 Oe and frequency 1093 Hz is measured. The nanodimensions of NZF/BT are observed dielectric constant up to 120 MHz. The optical activity of NZF/BT nanostructures is shown by Fluorescence spectra.

show abstract

Section: Resultsmentioning

confidence: 99%

Multiferroic Ni0.6Zn0.4Fe2O4-BaTiO3 nanostructures: Magnetoelectric coupling, dielectric, and fluorescence

Verma

Singh

Tripathi

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…The self-assembly procedure is discussed in detail in Ref. 41 and involved following 3 steps. (i) Preparation of NFO particles by co-precipitation techniques (vendor supplied BTO was used).…”

Section: Methodsmentioning

confidence: 99%

“…One of the nanoparticles, BTO or NFO, was functionalized azide groups and the other with alkyne groups. 41 Following this, the functionalized particles were heterogeneously linked together in the presence of a Cu(I) catalyst via the "click" reaction forming heterogeneous nanocomposites. [39][40][41] The core-shell structure was confirmed with electron microscopy and magnetic force microscopy.…”

Section: -6mentioning

confidence: 99%

“…41 Following this, the functionalized particles were heterogeneously linked together in the presence of a Cu(I) catalyst via the "click" reaction forming heterogeneous nanocomposites. [39][40][41] The core-shell structure was confirmed with electron microscopy and magnetic force microscopy. The magnetic and ferroelectric nature of the composites was confirmed with magnetization, ferromagnetic resonance and polarization P vs. E measurements.…”

Section: -6mentioning

confidence: 99%

“…We synthesized these core-shell nanocomposites by coating the ferroic nanoparticles with complementary coupling groups and allowing them to self-assemble. [38][39][40][41] We employed BTO (diameter = 50 nm) and NFO (diameter = 100 nm) nanoparticles for the assemblies. One of the nanoparticles, BTO or NFO, was functionalized azide groups and the other with alkyne groups.…”

Section: -6mentioning

confidence: 99%

See 2 more Smart Citations

High frequency magneto-dielectric effects in self-assembled ferrite-ferroelectric core-shell nanoparticles

et al. 2014

View full text Add to dashboard Cite

Magneto-dielectric effects in self-assembled core-shell nanoparticles of nickel ferrite (NFO) and barium titanate (BTO) have been investigated in the millimeter wave frequencies. The core-shell nano-composites were synthesized by coating 100 nm nickel ferrite and 50 nm barium titanate nanoparticles with complementary coupling groups and allowing them to self-assemble in the presence of a catalyst forming heterogeneous nanocomposites. Magneto-electric (ME) characterization of as-assembled particles has been carried out by measurements of the relative permittivity ɛr as a function of frequency f under an applied static magnetic field H over 16–24 GHz. Measurements show an H-induced decrease in ɛr of 1 to 1.5%. But a giant magneto-dielectric effect with an H-induced change in permittivity as high as 28% is measured under dielectric resonance in the samples. A strong ME coupling was also evident from H-tuning of dielectric resonance in the composites. A theory for the high frequency magneto-dielectric effect has been developed and consists of the following steps. First the Bruggeman model is used to estimate the effective dielectric constant for the shell consisting of the BTO particles and voids considered as spherical air-pores. Then the permittivity for the core and shell is estimated taking into consideration the sample porosity. Finally the H-dependence of the permittivity due to ME interactions is calculated from the free energy considerations. Estimated ɛr vs. H and dielectric resonance frequency vs. H characteristics are in general agreement with the data.

show abstract

Core‐Shell Heterostructures: From Particle Synthesis to Bulk Dielectric, Ferroelectric, and Multiferroic Composite Materials

Buscaglia

2016

Nanoscale Ferroelectrics and Multiferroics

View full text Add to dashboard Cite

Controlled self-assembly of multiferroic core-shell nanoparticles exhibiting strong magneto-electric effects

Cited by 48 publications

References 33 publications

Multiferroic Ni0.6Zn0.4Fe2O4-BaTiO3 nanostructures: Magnetoelectric coupling, dielectric, and fluorescence

Multiferroic Ni0.6Zn0.4Fe2O4-BaTiO3 nanostructures: Magnetoelectric coupling, dielectric, and fluorescence

High frequency magneto-dielectric effects in self-assembled ferrite-ferroelectric core-shell nanoparticles

Core‐Shell Heterostructures: From Particle Synthesis to Bulk Dielectric, Ferroelectric, and Multiferroic Composite Materials

Contact Info

Product

Resources

About