Ferromagnetic resonance spectroscopy of CoFeZr-Al2O3 granular films containing “FeCo core – oxide shell” nanoparticles

Kołtunowicz, Tomasz N.; Sidorenko, J.; Bayev, V.; Fedotova, Julia; Opielak, Marek; Marczuk, A.

doi:10.1016/j.jmmm.2016.08.016

Cited by 24 publications

(8 citation statements)

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“…The structural, magnetic, magnetoresistive and other properties of the metal-dielectric (FeCoZr) x (Al 2 O 3 ) 1-x nanocomposites produced by the ion-beam sputtering were investigated earlier [10,[14][15][16][17][18][19]. It was established by the TEM and XRD analyses that in such nanocomposites with concentration of metallic phase corresponding to the dielectric side of the metal-insulator transition (MIT), nanosized metallic nanoparticles formed by the FeCo alloy are randomly distributed in the Al 2 O 3 amorphous matrix [15].…”

Section: Introductionmentioning

confidence: 99%

Influence of oxide matrix on electron transport in (FeCoZr) x (Al 2 O 3 ) 1-x nanocomposite films

Свито

Fedotov

Saad

et al. 2017

Journal of Alloys and Compounds

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Electron transport in (Fe 0.45 Co 0.45 Zr 0.10 ) x (Al 2 O 3 ) 1-x granular nanocomposites (NCs) produced by the ion-beam sputtering of compound target was studied in the temperature range of 2-300 K.Conductivity of the films synthesized in the inert (Ar) atmosphere is determined below percolation threshold by the thermally activated electron tunneling over metallic granules at low temperatures and replaced by the Mott variable range hopping (VRH) with increasing temperature. Introduction of oxygen to the sputtering chamber suppresses VRH leading to retention of the thermally activated tunneling in the whole studied temperature range for the metallic phase atomic concentrations up to х = 0.62. The model of thermally activated tunneling over metallic granules gives an excellent agreement with experimental data when alumina matrix permittivity is considered as increasing with concentration of the metallic phase fraction in the films, which is due to increase in number of localized electronic states. The established influence of the sputtering atmosphere on the electron transport in nanocomposites is explained by reduction of concentration of the defects in matrix when oxygen is added to the sputtering atmosphere.

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Section: Introductionmentioning

confidence: 99%

Influence of oxide matrix on electron transport in (FeCoZr) x (Al 2 O 3 ) 1-x nanocomposite films

Свито

Fedotov

Saad

et al. 2017

Journal of Alloys and Compounds

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“…The orientation of samples in an external magnetic field was characterized by the polar angle θ B (an angle between the normal vector of sample surface and the vector of magnetic induction of external field B) and by the azimuth φ [23,24]. The θ B value of 0 • corresponds to the direction of external magnetic field perpendicular to the surface of a sample -out-of-plane (OOP).…”

Section: Methods and Experimental Resultsmentioning

confidence: 99%

“…The values of g-factor (g) and induction of demagnetizing field B d were determined using the dependence of B r value on the angle θ B between induction B and normal n [23] in assumption of uniform CoFeZr NPs distribution in CaF 2 matrix and homogeneous magnetization of metal nanoparticles (NPs). A quite homogeneous distribution of quasi-spherical FeCoZr NPs inside CaF 2 matrix at x ≤ 50 is clearly confirmed by transmission electron microscopy images presented in [25][26][27], while homogeneous magnetization of NPs is presumed by their small medium diameter within single-domain limit [25][26][27][28].…”

Section: Methods and Experimental Resultsmentioning

confidence: 99%

FERROMAGNETIC RESONANCE SPECTROSCOPY OF COFEZR-CAF<sub>2</sub> GRANULAR NANOCOMPOSITES

Kołtunowicz¹,

Bondariev²,

Sidorenko³

et al. 2020

PIER M

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Results of the study of magnetic properties of nanocomposite samples (CoFeZr) x (CaF 2 ) (100−x) (31 at.% ≤ x ≤ 47 at.%) produced in argon (Ar) and argon with oxygen (Ar with O 2 ) sputtering atmosphere are presented in this paper. The magnetic resonance spectroscopy at room temperature using continuous wave X-band electron spin resonance (ESR) was used for analysis of samples magnetic properties. After analysis it is established that in the case of samples produced in argonsputtering atmosphere the value of g increases with the rise of metal content and for samples produced in argon with oxygen atmosphere the value g decrease with the rise of x. Such a behavior of g(x) is explained by the presence of core-shell structure of NPs represented by ferromagnetic core and antiferromagnetic core that results in quenching of orbital motion of electrons.

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“…The tests were done to verify the possibility of using such a heating system in the recent developed device for molybdenum sheet deep drawing without the need of using a complex and expensive hot zone [9,15,18].…”

Section: Resultsmentioning

confidence: 99%

Molybdenum Sheet Local Resistance Heating Test Device

Mitka

Bašťovanský

Brumerčík

et al. 2017

Adv. Sci. Technol. Res. J.

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Large demand for bulk of sapphire optical products, which are widely used as illuminators, optical windows in aviation and aeronautics etc., generates the inquiry of effective production of high quality industrial crystals. The technology of crystal growth with the horizontal single crystal sapphire crystallization method is based on putting the crystal seed into the front of the crucible resistant to temperatures up to 2150°C. Without encompassment of the production technology of this special container made from thin molybdenum sheet is not realistic to consider the productive exploitation of horizontal crystallization systems in engineering practice. This paper presents the analysis of the possibility of the local resistance of molybdenum sheet heating by its deep drawing to obtain better drawing properties by increased blank temperature.

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Ferromagnetic resonance spectroscopy of CoFeZr-Al2O3 granular films containing “FeCo core – oxide shell” nanoparticles

Cited by 24 publications

References 10 publications

Influence of oxide matrix on electron transport in (FeCoZr) x (Al 2 O 3 ) 1-x nanocomposite films

Influence of oxide matrix on electron transport in (FeCoZr) x (Al 2 O 3 ) 1-x nanocomposite films

FERROMAGNETIC RESONANCE SPECTROSCOPY OF COFEZR-CAF<sub>2</sub> GRANULAR NANOCOMPOSITES

Molybdenum Sheet Local Resistance Heating Test Device

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