Disordered surface spins induced large exchange anisotropy in single-phase Sm3+ ions substituted nickel ferrite nanoparticles

Ghosh, Mritunjoy Prasad; Mukherjee, Sayak

doi:10.1016/j.jmmm.2019.165320

Cited by 50 publications

(48 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Usually, in a solid solution of ferrites, a linear change in lattice constant with concentration of the components is observed [33,51]. It is observed in this study that CoFe 2 O 4 nanoparticle size increases while the lattice parameter decreases with increasing Cu, in good agreement with the literature [66]. These changes can be explained as follows.…”

Section: Cu Concentration Effect On Lattice Parameter Of Cobalt Ferri...supporting

confidence: 89%

“…The value of u increases slightly with the increase in Cu concentration, and can be attributed to the migration of Fe 3+ ions from B sites to A sites [20]. The tetrahedral lattice sites are slightly smaller in respect to metal ions, which results in shrinking of octahedral sites to settle the A sites [20,[66][67][68].…”

Section: Cu Concentration Effect On Lattice Parameter Of Cobalt Ferri...mentioning

confidence: 99%

See 1 more Smart Citation

Formation Mechanism and Lattice Parameter Investigation for Copper-Substituted Cobalt Ferrites from Zingiber officinale and Elettaria cardamom Seed Extracts Using Biogenic Route

Barkat¹,

Afzal²,

Khan³

et al. 2022

Materials

View full text Add to dashboard Cite

Biogenic routes for the synthesis of nanoparticles are environmentally friendly, nontoxic, biocompatible, and cost-effective compared to traditional synthesis methods. In this study, cobalt ferrite was synthesized using Zingiber officinale and Elettaria cardamom Seed extracts. Effect of copper contents (x = 0.0, 0.3, 0.6 and 0.9) on the plant extracted Cux(Co1−xFe2O4) was investigated by XRD, SEM, EDX, UV-Vis., PL, FE-SEM, FTIR and photocatalytic activity. XRD results revealed that nanoparticles exhibit a cubical spinel structure with an average diameter of 7–45 nm, calculated by the Debye Scherer formula. The value of the lattice parameter decreased from 8.36 Å to 8.08 Å with substitution of copper, which can be attributed to mismatch of ionic radii of Cu2+ (0.73 Å) and Co2+ (0.74 Å) ions. SEM analysis showed that nanoparticles exhibit a spherical shape (~13 nm diameter) for undoped samples and low Cu concentration, while they changed to a hexagonal structure at higher Cu concentration (x = 0.9) with a diameter ~46 nm and a decreased degree of agglomeration. FE-SEM further confirmed the nanoparticles’ size and shape. EDX analysis confirmed the presence of cobalt, iron, and oxygen without contamination. The optical absorption spectra of UV-vis and PL showed red-shift, which can be accredited to larger crystalline sizes of nanoparticles. FTIR spectra showed two main bands at 410 and 605 cm−1, indicating the presence of intrinsic vibrations of the octahedral and tetrahedral complexes, respectively. The photocatalytic activity of Co0.4Cu0.6 Fe2O4 nanoparticles was investigated using methylene blue (MB) and methyl orange (MO) dyes under visible light irradiation. The degradation rate (93.39% and 83.15%), regression correlation coefficient (0.9868 and 0.9737) and rate constant (0.04286 and 0.03203 rate·min−1) were calculated for MB and MO, respectively. Mechanisms for the formation and photocatalytic activity of Cu-substituted plant-extracted cobalt ferrite were discussed. The Co0.4Cu0.6 Fe2O4 nanoferrite was found to be an efficient photocatalyst, and can be exploited for wastewater treatment applications for MB/MO elimination.

show abstract

Section: Cu Concentration Effect On Lattice Parameter Of Cobalt Ferri...supporting

confidence: 89%

Section: Cu Concentration Effect On Lattice Parameter Of Cobalt Ferri...mentioning

confidence: 99%

Formation Mechanism and Lattice Parameter Investigation for Copper-Substituted Cobalt Ferrites from Zingiber officinale and Elettaria cardamom Seed Extracts Using Biogenic Route

Barkat¹,

Afzal²,

Khan³

et al. 2022

Materials

View full text Add to dashboard Cite

show abstract

“…The magnetization of both FC and zero‐field‐cooling (ZFC) curves increases from 2.5 to 12.5 emu g −1 as the temperature decreases from 300 to 99 K. Thereafter, FC and ZFC curves separate from each other with further decrease in temperature. The maximum temperature in the ZFC curve is the average blocking temperature ( T B ) of the nanoparticles, [ 29 ] which is concluded to be 99 K for Fe@Fe‐oxide nanoparticles. The thermal fluctuation dominates the magnetic behaviors when the temperature is above T B , inducing fluctuations of the ZFC/FC curve due to the randomness of the thermal field.…”

Section: Resultsmentioning

confidence: 99%

Connection Between Intrinsic Interfacial Frozen Spins and Exchange Bias Effect in Core@Shell Iron@Iron‐Oxide Nanoparticles

Hong

Shen

et al. 2023

Physica Status Solidi (b)

View full text Add to dashboard Cite

Exchange bias is a common phenomenon that appears at the interfaces between ferromagnetic and ferrimagnetic materials due to the presence of frozen spins. However, systematic quantification of their intrinsic correlation remains to be a challenge. Herein, the exchange bias induced by frozen spins is assumed as the synergy of an effective static magnetic field and an effective anisotropy, and thus the effect of intrinsic frozen spins at core@shell interfaces of iron@iron‐oxide nanoparticles is estimated. It is confirmed that the shift of the hysteresis loop is 2322 Oe and the coercivity increases from 360 to 1590 Oe. Using micromagnetic simulations, such a hysteresis loop is reconstructed by introducing an effective static magnetic field of 7360 Oe and an effective anisotropy of 45 × 103 J m−3. Therefore, a connection between the intrinsic interfacial frozen spins and the exchange bias effect is established from a mesoscale perspective, mediated by the effective magnetic field and effective anisotropy. The results can provide an understanding of exchange bias effect and promote applications of ferromagnetic/ferrimagnetic heterostructures.

show abstract

“…According to the reports, even a minute substitution affects structural, electrical, and magnetic properties signi cantly. These property alterations have been attributed to larger ionic radii, magnetic ordering in rare earth metal ions [10][11][12][13][14][15][16][17][18][19]. However, it is di cult to substitute a larger quantity of rare earth dopant ions due to the large size and tendency to occupy the octahedral site replacing the smaller Fe + 3 ions which may lead to the formation of a secondary phase [20][21][22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Influence of B-Site Gd+3 Substitution on Various Properties of Co-Ferrite Nanoparticles

Salgaonkar

Gad

2021

Preprint

View full text Add to dashboard Cite

The effect of rare earth (Gd+ 3) substitution on various properties of nanocrystalline cobalt ferrite material with composition CoFe2 − xGdxO (x = 0, 0.02, 0.04, 0.06, 0,08, 0.1) prepared using combustion method was investigated. The alterations produced in the structural parameters of the spinel lattice of cobalt ferrite were investigated using X-ray diffraction (XRD). The structural parameter such as Lattice constant, mass density, strain, and crystallite size showed irregular variation triggered due to Rare earth inclusion. The chemical composition analysis was done using energy-dispersive X-ray spectroscopy (EDS). Morphological investigations were done using a scanning electron microscope (SEM). The dependence of A.C. susceptibility and other crucial magnetic properties on rare earth content in the ferrite matrix was also investigated. The temperature dependence of electrical properties such as DC resistivity, dielectric constant, and dielectric loss was also investigated to study the alterations caused due to incorporation of rare earth ions.

show abstract

Disordered surface spins induced large exchange anisotropy in single-phase Sm3+ ions substituted nickel ferrite nanoparticles

Cited by 50 publications

References 39 publications

Formation Mechanism and Lattice Parameter Investigation for Copper-Substituted Cobalt Ferrites from Zingiber officinale and Elettaria cardamom Seed Extracts Using Biogenic Route

Formation Mechanism and Lattice Parameter Investigation for Copper-Substituted Cobalt Ferrites from Zingiber officinale and Elettaria cardamom Seed Extracts Using Biogenic Route

Connection Between Intrinsic Interfacial Frozen Spins and Exchange Bias Effect in Core@Shell Iron@Iron‐Oxide Nanoparticles

Influence of B-Site Gd+3 Substitution on Various Properties of Co-Ferrite Nanoparticles

Contact Info

Product

Resources

About