Large tunability of Néel temperature by growth-rate-induced cation inversion in Mn-ferrite nanoparticles

In this paper, we reported a comparative study of structural and magnetic properties of MnFe 2 O 4 /ZnO nanocomposite and MnFe 2 O 4 nanoparticles. The samples were prepared with a simple thermal decomposition method and then were characterized through thermogravimetry (TG) and differential thermal analysis (DTA), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) images, and vibrating sample magnetometry (VSM) at different temperatures. TG curves showed that pure samples can be obtained at 400 • C. XRD pattern of composite sample confirmed coexistence of crystalline cubic spinel Mn-ferrite and hexagonal zinc oxide phases. The estimated lattice parameter of MnFe 2 O 4 nanoparticles, a = 8.39Å, was smaller than bulk value (a = 8.51Å) due to finite size effects. The magnetization of both samples followed the Bloch law with almost the same Bloch constant of β ∼ 5 × 10 −5 (K −3/2 ) showing similar spin wave excitation mechanisms in the samples. However, the VSM measurements indicated that increase of coercivity (H c ) of composite sample with decreasing the temperature is faster when compared with pure ferrite.

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“…Similar results have been reported in literature [11,[23][24][25]. Finite size effects such as cation distribution and oxidation [27].…”

Section: Resultssupporting

confidence: 90%

Effect of ZnO on Structural and Magnetic Properties of MnFe2O4/ZnO Nanocomposite

Aslibeiki

Kameli

2015

J Supercond Nov Magn

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“…to Mn 3? and different cation distributions of ferrite nanoparticles can decrease the lattice constant [31,32]. Density of the prepared samples was calculated using the Archimedes principle from precise measurements of the dry, saturated and suspended weight.…”

Section: Xrd Analysismentioning

confidence: 99%

MnCrxFe2−xO4 Nanoparticles: Magnetic and Microwave Absorption Properties

Baykal

Genç

Elmal

et al. 2015

J Inorg Organomet Polym

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Chromium substituted Mn nanospinel ferrites having the formula MnCr x Fe 2-x O 4 (0.0 B x B 1.0) have been synthesized using the microwave-assisted combustion synthesis. The composition, structural, spectroscopic features of the products were studied by X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. XRD investigations indicated the formation of single-phased cubic spinel structure for all products. Lattice parameters of the products represented the continuous decrease with increasing the substitution of Cr 3? . The saturation magnetization of undoped sample appeared to be highest and as Cr 3? concentration increases magnetization of the samples decreases. There is one reflection loss minimum in all doped samples at around 13 GHz with magnitude of -12 dB mechanism of which is explained by quarter wave cancellation model.

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“…On the other hand, non-magnetic metal ions such as Zr is known to preferably occupy A-sites (i = 0) [4]. It is important to mention here that anomalous variations in the exclusive preferential occupation of many metal ions such as Mn 2+ and Ni 2+ ions have been reported, and correlated to the preparation and processing conditions employed to synthesize the nanoferrites [5][6][7].…”

Section: Introductionmentioning

confidence: 96%

Electrical and Magnetic Properties of Zr4+ and Ni2+ Ions Substituted Mn–Cu Spinel Ferrites

Faraz

Ahmad

2011

J Supercond Nov Magn

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The Mn-Cu nanoferrites of composition Mn 0.5 Cu 0.5 Fe 2 − 2x Ni x Zr x O 4 (0.00 ≤ x ≤ 0.80) were synthesized by incorporating dopant Zr 4+ and Ni 2+ cations via a chemical coprecipitation technique. The single phase of the prepared spinel nanoferrites with particle sizes 15-31 nm was confirmed by XRD. Both electrical and magnetic properties are found to depend on the x contents and explained by considering the Zr 4+ and Ni 2+ cations distribution, displacement of the Fe 3+ ions by dopants, changes in magnetic moment at tetrahedral A site and octahedral B site, Fe 3+ (A)-O 2 -Fe 3+ [B] linkages and extent of the primary superexchange interactions (A)-O-[B] of the Fe 3+ ions on the A and B-sites. DC resistivity, saturation magnetization (M s ), remanence (M r ) and Bohr magneton (n B ) are observed to increase up to x ≤ 0.40, while these parameters fall at relatively higher value of x ≥ 0.60.

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Large tunability of Néel temperature by growth-rate-induced cation inversion in Mn-ferrite nanoparticles

Cited by 29 publications

References 36 publications

Effect of ZnO on Structural and Magnetic Properties of MnFe2O4/ZnO Nanocomposite

Effect of ZnO on Structural and Magnetic Properties of MnFe2O4/ZnO Nanocomposite

MnCrxFe2−xO4 Nanoparticles: Magnetic and Microwave Absorption Properties

Electrical and Magnetic Properties of Zr4+ and Ni2+ Ions Substituted Mn–Cu Spinel Ferrites

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