FMR and DSC study of maghemite nanoparticles in PMMA polymer matrix

Typek, J.; Guskos, N.; Szymczyk, Anna; Petridis, Dimitris

doi:10.1016/j.jnoncrysol.2008.06.090

Cited by 8 publications

(7 citation statements)

References 25 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Iron hydroxide gel was used as a precursor for the NP synthesis, and the FMR experiments exposed the temperature range of a superparamagnetic regime (60-290 K) and the blocking temperature, T B ∼ 60 K. The significance of the dipole-dipole interaction for a high concentration of maghemite and temperatures above 220 K was demonstrated. 313 Owens studied the ferromagnetic resonance of magnetic field oriented magnetite NPs in frozen ferrofluids: it was shown that by freezing magnetic NPs suspended in a fluid in a magnetic field it is possible to determine the orientational dependence of the FMR spectrum and abstract parameters such as the g value and magnetic anisotropy constant, K.…”

Section: Characterization Methods For Magnetic Nanostructuresmentioning

confidence: 99%

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

2018

View full text Add to dashboard Cite

Nanostructures have attracted huge interest as a rapidly growing class of materials for many applications. Several techniques have been used to characterize the size, crystal structure, elemental composition and a variety of other physical properties of nanoparticles. In several cases, there are physical properties that can be evaluated by more than one technique. Different strengths and limitations of each technique complicate the choice of the most suitable method, while often a combinatorial characterization approach is needed. In addition, given that the significance of nanoparticles in basic research and applications is constantly increasing, it is necessary that researchers from separate fields overcome the challenges in the reproducible and reliable characterization of nanomaterials, after their synthesis and further process (e.g. annealing) stages. The principal objective of this review is to summarize the present knowledge on the use, advances, advantages and weaknesses of a large number of experimental techniques that are available for the characterization of nanoparticles. Different characterization techniques are classified according to the concept/group of the technique used, the information they can provide, or the materials that they are destined for. We describe the main characteristics of the techniques and their operation principles and we give various examples of their use, presenting them in a comparative mode, when possible, in relation to the property studied in each case.

show abstract

Section: Characterization Methods For Magnetic Nanostructuresmentioning

confidence: 99%

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

2018

View full text Add to dashboard Cite

show abstract

“…The relaxation processes transfer excited energy between correlated spin systems could influence the broadening processes. The decrease of the integrated intensity with temperature decrease in high temperature range is a characteristic behaviour of magnetic nanoparticles (or clusters) in the form of agglomerates embedded in a nonmagnetic matrix [9,10,12]. The resonance line 1 exhibits a smoother variation of integrated intensity with temperature because the correlated spin system connected with line 1 consist in higher concentration and it allows for the possibility of different reorientation processes of the magnetic moments that could be responsible for the strong anisotropic magnetic interactions.…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13]. The mixed n(Fe 2 O 3 )/(1 − n)ZnO nanocomposites could form two coexisting important magnetic phases (γ-Fe 2 O 3 and ZnFe 2 O 4 ) and for higher value of n they are dominated by iron oxide [14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

FMR Study of Temperature Dependence of Magnetic Properties of Nanocrystalline 0.90(Fe₂O₃)/0.10ZnO

et al. 2011

Self Cite

View full text Add to dashboard Cite

The nanocrystalline mixed system 0.90(Fe2O3)/0.10ZnO has been prepared by coprecipitation and calcination processes. The phase composition of samples was determined by X-ray diffraction. The studied nanocrystalline sample is dominated by phase Fe2O3 but very small amounts of ZnO and ZnFe2O4 phases were also identified. The ferromagnetic resonance investigations of the obtained sample have been carried out in the temperature range from liquid helium to room temperature. The asymmetrical and very intense magnetic resonance line was recorded at all temperatures. A significant shift of spectra towards lower magnetic fields with decreasing temperature was observed. A very good fitting by two Lorentzian functions has been obtained which suggested the existence of a strong anisotropic magnetic interaction. Some similarities in behaviour of ferromagnetic resonance parameters of the present sample and the 0.95Fe 2 O 3 Fe2O3/0.05ZnO sample were noticed but the parameters values were essentially different. The gradients ∆H r /∆T (where H r is the resonance field), the broadening processes of the resonance lines as well as the line amplitudes were changing more intensely changing with temperature in comparison to sample 0.95Fe 2 O 3 Fe2O3/0.05ZnO. The following values ∆H r /∆T are obtained: 16.7(1) Gs/K and 20.7(1) Gs/K over the 60 K temperatures where below 40 K is 41.5(1) Gs/K and 56.0(1) Gs/K. The reorientation processes were more active at low temperatures for smaller concentrations of magnetic nanoparticles.

show abstract

“…Ceramic sample of (Dy 0.375 Y 0.625 ) 2 Cu 2 O 5 has been prepared by heating in air of appropriate stoichiometric amounts of metal oxides and was described elsewhere [14]. X-ray characterization showed that the sample is single phase with the following orthorhombic lattice parameters: a = 1.0817 nm, b = 0.3502 nm, c = 1.2462 nm.…”

Section: Methodsmentioning

confidence: 99%

“…It has been estimated that J 0 /k ~ 260 K, |J 1 /J 0 | ~ 1/380, |J 2 /J 0 | ~ 1/1100 [13]. [14][15][16][17]. Only signal from the copper(II) ions has been registered by conventional X-band EPR spectroscopy.…”

Section: Originalmentioning

confidence: 99%

Competing magnetic interactions in (Dy_0.375Y_0.625)₂Cu₂O₅ solid solution studied by EPR

Typek

2007

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

structure has been found in the EPR spectrum and the values of appropriate exchange constants connected with a hierarchy of exchange interactions has been calculated. At about 40 K a dimensional crossover from 2D to 3D behaviour has been observed in the temperature dependence of the product of the EPR integrated intensity and temperature. At high temperatures (T > 200 K) the EPR spectrum is suggestive of the presence of defect centres consisting of antferromagnetically coupled copper spins, forming dimers with the S = 0 ground state.

show abstract

FMR and DSC study of maghemite nanoparticles in PMMA polymer matrix

Cited by 8 publications

References 25 publications

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

FMR Study of Temperature Dependence of Magnetic Properties of Nanocrystalline 0.90(Fe₂O₃)/0.10ZnO

Competing magnetic interactions in (Dy_0.375Y_0.625)₂Cu₂O₅ solid solution studied by EPR

Contact Info

Product

Resources

About

FMR and DSC study of maghemite nanoparticles in PMMA polymer matrix

Cited by 8 publications

References 25 publications

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

FMR Study of Temperature Dependence of Magnetic Properties of Nanocrystalline 0.90(Fe2O3)/0.10ZnO

Competing magnetic interactions in (Dy0.375Y0.625)2Cu2O5 solid solution studied by EPR

Contact Info

Product

Resources

About

FMR Study of Temperature Dependence of Magnetic Properties of Nanocrystalline 0.90(Fe₂O₃)/0.10ZnO

Competing magnetic interactions in (Dy_0.375Y_0.625)₂Cu₂O₅ solid solution studied by EPR