Structural, electrical, magnetic and dielectric properties of rare-earth substituted cobalt ferrites nanoparticles synthesized by the co-precipitation method

2014 ◽  
Vol 355 ◽  
pp. 201-209 ◽  
Author(s):  
A.K. Nikumbh ◽  
R.A. Pawar ◽  
D.V. Nighot ◽  
G.S. Gugale ◽  
M.D. Sangale ◽  
...  
Keyword(s):  
Rare Earth ◽  
Dielectric Properties ◽  
Precipitation Method ◽  
Cobalt Ferrites ◽  
Magnetic And Dielectric Properties ◽  
Co Precipitation

Structure and Dielectric Properties of (Gd0.4Sm0.5Yb0.1)2(Zr1-xCex)2O7 Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 394-397
Author(s):  
Ling Liu ◽  
Qiang Xu ◽  
Fu Chi Wang
Keyword(s):  
Rare Earth ◽  
Dielectric Properties ◽  
Pyrochlore Structure ◽  
Microwave Frequency ◽  
Phase Region ◽  
Dielectric Constants ◽  
Precipitation Method ◽  
Low Dielectric ◽  
Pyrochlore Type ◽  
Co Precipitation

Complex rare-earth zirconates (Gd0.4Sm0.5Yb0.1)2(Zr1-xCex)2O7 (x=0, 0.3, 0.4) powders were synthesized by co-precipitation method. XRD and SEM results revealed that the complex rare-earth zirconates with single pyrochlore structure were prepared and no other phases existed among the grains. The dielectric properties of these compounds were investigated at low and microwave frequencies. It was found that they have intermediate dielectric constants and low dielectric loss in the whole frequency region, and they show the dielectric permittivity with weak frequency dependence. Substituting Zr4+ by Ce4+ leaded to smaller permittivity. Meanwhile, the dielectric contant values increase with increasing in the r(A3+)/r(B4+) value in the pyrochlore-type phase region, which can be explained by the increase in the degree of ordering of oxygen vacancy. This new series of pyrochlore type oxides would be potential candidates for electronic ceramic applications and microwave frequency components.

scholarly journals Structural, magnetic and dielectric properties of ultrafine nickel substituted cobalt ferrite− reduced graphene oxide nanocomposites

2020 ◽  
Author(s):  
N. Ambikeswari ◽  
S. Manivannan
Keyword(s):  
Graphene Oxide ◽  
Dielectric Properties ◽  
Reduced Graphene Oxide ◽  
Cobalt Ferrite ◽  
Precipitation Method ◽  
One Pot ◽  
Reduced Graphene ◽  
Magnetic And Dielectric Properties ◽  
Co Precipitation ◽  
High Dielectric

Abstract Nickel substituted cobalt ferrite − reduced graphene oxide (NCF-RGO) composite was synthesized using a facile one-pot chemical co-precipitation method. The addition of graphene oxide (GO) leads to the dimensional decrease of NCF nanoparticles (< 10 nm) in the composite, which controls the magnetic and dielectric properties. Nickel with lower ionic radius, compared to cobalt and its substitution in the composite along with the incorporation of GO results in the transition of ferromagnetic to superparamagnetic ordering. A large magnetisation of 51.63 emu/g and a high dielectric constant of 3.92 x 10 6 (at 100 Hz) were also developed from the composite. The conjugated mechanism of magnetic combined electrical property, with a high charge–storing capability and tuneable magnetization, enables its potential use in magnetic flipping or switching devices and data storing systems.

scholarly journals Influence of Co ion doping on the microstructure, magnetic and dielectric properties of Ni1-xCoxFe2O4 ceramics

2018 ◽  
Vol 12 (4) ◽  
pp. 335-341 ◽  
Author(s):  
Jihua Zou ◽  
Rongli Gao ◽  
Chunlin Fu ◽  
Wei Cai ◽  
Gang Chen ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Saturation Magnetization ◽  
Spinel Phase ◽  
Impedance Analysis ◽  
Magnetic Behaviour ◽  
Precipitation Method ◽  
Co Doping ◽  
Ion Doping ◽  
Magnetic And Dielectric Properties ◽  
Co Precipitation

Ni1-xCoxFe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8) ceramics were prepared by chemical co-precipitation method and the effect of Co ion doping on the microstructure, magnetic and dielectric properties has been investigated. The results show that the synthesized ceramics display only spinel phase of Ni1-xCoxFe2O4, without other apparent impurities found. The lattice of Ni1-xCoxFe2O4 crystal structure was distorted as a result of the incorporation of Co ion, and the lattice parameters increase with the increase of Co ion content. The grain size decreases slightly with increasing the content of Co ion, indicating a change of particle size and morphology at higher doping content. The results of impedance analysis shows that the sample doped with 80 at.%Co possesses the maximal dielectric constant, while the pure NiFe2O4 sample shows the minimal value when the frequency is below 0.1MHz. The M-H loops of these ceramics exhibit highly magnetic nature and the saturation magnetization. The remnant magnetization increases linearly with the increase of Co-concentration in nickel ferrite while the coercive field (Hc) shows non-monotonic variation with Co content. The minimal and maximal values of Hc can be obtained when the Co concentrations are 40 and 80 at.%, respectively. The highest value of the saturation magnetization is 63 emu/g obtained with 80 at.% Co doping while the lowest value is ~31 emu/g for the pure NiFe2O4 ceramics. The abnormal magnetic behaviour is due to the A-B super exchange interaction when magnetic Co2+ ions are added.

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