Correlation between the structural state and magnetoresistive properties of granular Co Ag100- alloy thin films

Shpetnyi, I. O.; Vorobiov, Serhii; Kondrakhova, D. M.; Шевченко, М.С.; Duplik, L.V.; Панина, Л. В.; Grebinaha, V.I.; Gorobets, Yu. I.; Satrapinskyy, Leonid; Luciński, T.

doi:10.1016/j.vacuum.2020.109329

Cited by 14 publications

(11 citation statements)

References 39 publications

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“…The study of magnetoresistive properties was carried out at room temperature on an automatic measuring system in two geometric dimensions -transverse and longitudinal [23]. Measurements were performed by applying a magnetic field with an amplitude in the range Bmax ± 0.45 T using a 4-point measurement scheme.…”

Section: Methodsmentioning

confidence: 99%

“…One such effect is the phenomenon of giant magnetoresistance (GMR) in multilayers and granular film alloys [7][8][9][10]. The discovery of the GMR phenomenon has aroused widespread interest in these nanostructures due to the possibility of their application in spintronics, sensor electronics, biotechnology, medicine, instrumentation and other fields [1,2,[11][12][13][14][15]. The effect of giant magnetoresistance is observed in granular magnetic films based on alloys of Co-Ag, Fe-Ag, Co-Cu, Permalloy-Ag, Permalloy-Cu, where magnetic granules with a size of units up to 100 nm are randomly placed in the volume of the non-magnetic matrix [13,14,16,17].…”

Section: Introductionmentioning

confidence: 99%

“…The discovery of the GMR phenomenon has aroused widespread interest in these nanostructures due to the possibility of their application in spintronics, sensor electronics, biotechnology, medicine, instrumentation and other fields [1,2,[11][12][13][14][15]. The effect of giant magnetoresistance is observed in granular magnetic films based on alloys of Co-Ag, Fe-Ag, Co-Cu, Permalloy-Ag, Permalloy-Cu, where magnetic granules with a size of units up to 100 nm are randomly placed in the volume of the non-magnetic matrix [13,14,16,17]. The GMR effect is the result of spin-dependent scattering of conduction electrons at the interface between the nonmagnetic matrix and the magnetic granule or in the volume of the magnetic granule [6,17].…”

Section: Introductionmentioning

confidence: 99%

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Structural-Phase State and Magnetotransport Properties of Thin Film Alloys Based on Permalloy and Copper

Shpetnyi¹,

Tyschenko²,

Pak³

et al. 2021

J. Nano- Electron. Phys.

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The paper presents the results of research influence of composition on structural-phase state and magnetoresistive properties of as-deposited and heat-treated at temperatures Ta ≤ 900К samples film alloys based on Py and Cu. Samples of thin film alloys with a thickness of d  25 nm in the range of 19 ≤ cCu ≤ 69 (where cCu is the concentration of Cu, at.%) were obtained by the method of co-evaporation in vacuum from two independent evaporators. The structural-phase state of the samples of film alloys at cCu  19 at.%, 34 at.% and 61 at.% was investigated by the method of transmission electron microscopy. The structure of thin films in both as-deposited and annealed at Ta ≤ 900 K state consists of quasi granules with permalloy embedded in a nonmagnetic Cu matrix. The phase state of the samples at cCu  19 at.% and cCu  34 at.% in the as-deposited state and after heat treatment at Ta  600 K corresponded to fcc-NixFe (x ≈ 3) + fcc-Cu. After heat treatment at temperatures of 700  Ta  900 К, the phase state of the samples at cCu  19 at.% and cCu  34 at.% corresponded to Ni3Fe + fcc-Cu. For the film alloy sample at cCu  61 at.% in the as-deposited state and after heat treatment at temperatures of 600  Ta  900 К, the phase state corresponded to fcc-NixFe (x ≈ 3) + fcc-Cu. Studies of the magnetoresistive properties of film samples showed that the film samples in the entire range of compositions of 19 ≤ cCu ≤ 69 at.% were characterized by isotropic magnetoresistance. The maximum value of the giant magnetoresistance was observed for the sample with cCu  34 at.% Both in the as-deposited state and after heat treatment at temperatures of 600  Ta  900 К. Heat treatment of samples in the temperature range of 600  Ta  900 К had almost no effect on the value of GMR films at 19 ≤ cCu ≤ 51 at.%.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structural-Phase State and Magnetotransport Properties of Thin Film Alloys Based on Permalloy and Copper

Shpetnyi¹,

Tyschenko²,

Pak³

et al. 2021

J. Nano- Electron. Phys.

View full text Add to dashboard Cite

show abstract

“…GMR occurs when the sample is magnetically inhomogeneous, and the distance between the gran-ules is proportional to the mean free path of electrons [11]. The authors [12,13] showed that the thickness of granular films affects their structural state. Subsequently, the magnetic and magnetoresistive properties of granular film systems depend on the structural state of the film sample: the size and shape of the granules and the distance between them [8,14].…”

Section: Introductionmentioning

confidence: 99%

“…The decrease in the thickness of granular films causes dimensional effects that affect the structure of the samples and, accordingly, the magnetic and magnetoresistive properties. In [4,13], it was shown that in the case of relatively small (d ≤ 40 nm) total film thickness, the granular system has some peculiar properties. In a film alloy based on Co and Cu at small thicknesses of the film system, the islands of the magnetic component will act as granules, which will be localized between the crystallites of the fcc-Cu(Co) solid solution (s.s.).…”

Section: Introductionmentioning

confidence: 99%

Magnetic and Magnetoresistive Properties of Thin Film Alloys Based on Cobalt and Copper

Shpetnyi¹

2020

J. Nano- Electron. Phys.

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This work presents the results of a study of the influence of dimensional and concentration effects on magnetoresistive and magnetic properties and structural-phase state of annealed at Ta  700 K samples of thin film alloys based on Co and Cu with thickness d  40 nm in a wide range of total concentrations of Co (18 ≤ cCo ≤ 69 at. %). The samples were obtained by the method of co-evaporation in vacuum using two independent electron guns. It was found that samples of thin film alloys with a total concentration of cobalt cCo ≤ 22 at. % are characterized mainly by a superparamagnetic state in which hcp-Co granules with size L  5÷12 nm were placed in a matrix of Cu(Co) solid solution (s.s.) based on fcc-Cu. The increase in the total concentration of Co in thin film alloys to cCo  37 at. % led to an increase in the size of the magnetic granules to L  7÷20 nm and a decrease in the distance between them. In samples of thin film alloys with a cobalt concentration of 56 ≤ cCo ≤ 69 at. %, hcp-Co granules with size L  8÷25 nm were combined into ferromagnetic clusters, and the volume between the clusters was filled with fcc-Cu(Co) s.s.. The maximum giant magnetoresistance (GMR) values, measured in an external magnetic field Hmax  15 kOe at room temperature, were obtained for a sample with a total concentration of cobalt cCo  22 at. %. The amplitude of GMR values was 3.8 % and 4.1 % in the perpendicular and longitudinal measurement geometries, respectively. Thin film alloys with a total cobalt concentration of 18 ≤ cCo ≤ 22 at. % were characterized by isotropic magnetoresistance. The increase in the total concentration of cobalt in thin film alloys to cCo ≥ 28 at. % led to the emergence of magnetic anisotropy and anisotropic magnetoresistance. This may be due to the appearance of ferromagnetic interactions between cobalt granules. Low-temperature measurements of magnetoresistance at Тmeas  5 K of the sample with a total cobalt concentration cCo  18 at. % showed an increase in the amplitude of GMR by 2.1 times (GMR  11.1 %) compared with the amplitude of GMR  5.18 % measured at room temperature in an external magnetic field Hmax  90 kOe. With increasing measurement temperature to T  350 K the amplitude of GMR decreased and amounted to 4.5 %. This is due to the increase in electron scattering by phonons with increasing temperature.

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Giant Magnetoresistance (GMR) Materials and Devices for Biomedical and Industrial Applications

Saha

et al. 2022

Spintronics

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Correlation between the structural state and magnetoresistive properties of granular Co Ag100- alloy thin films

Cited by 14 publications

References 39 publications

Structural-Phase State and Magnetotransport Properties of Thin Film Alloys Based on Permalloy and Copper

Structural-Phase State and Magnetotransport Properties of Thin Film Alloys Based on Permalloy and Copper

Magnetic and Magnetoresistive Properties of Thin Film Alloys Based on Cobalt and Copper

Giant Magnetoresistance (GMR) Materials and Devices for Biomedical and Industrial Applications

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