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The influence of the state of interfaces on the magnetoresistive properties of Co/Cu superlattices has been studied by the methods of nuclear magnetic resonance and X-ray reflectometry. It has been found that the magnetron-sputtered superlattices with the highest value of the giant magnetoresistance effect have the largest fraction of highly perfect Co/Cu interlayer boundaries, as well as practically the smallest fraction of cobalt atoms localized in the interfaces. [ABSTRACT FROM AUTHOR]

Abstract—The magnetoresistive characteristics of magnetic metallic Fe/Cr and Co90Fe10/Cu superlattices subjected to irradiation with accelerated Аr+ ion beams with an energy of 10 keV at the fluences F = 1013–1016 cm–2 are studied in this work. It was found that, at F ≤ 6 × 1014 cm–2, the studied superlattices retain their functional characteristics. Causes for a decrease in the magnetoresistance of superlattices with a subsequent increase in the fluence are discussed. It was concluded that the radiation stability of the advanced modern Co90Fe10/Cu superlattices is higher than that of the model Fe/Cr superlattices. [ABSTRACT FROM AUTHOR]

Abstract—The structure and magnetoresistive properties of Ta(5 nm)/NiFeCr(5 nm)/[FM(tFM)/Cu(2.2 nm)]n/ Ta(5 nm) superlattices prepared by magnetron sputtering are studied in this work. The ferromagnetic layer thickness tFM is varied in a 1.1–1.5 nm range. The Co90Fe10, Co85Fe12Ni3, Co77Fe17Ni6, and Co70Fe20Ni10 alloys with an fcc structure and close saturation magnetization values are used as the ferromagnetic (FM) materials. It is shown that, as the Ni and Fe contents in the CoFeNi alloy increase, the magnetoresistance of superlattices containing eight bilayers remains high and equal to 24–28%; in this case, the twofold decrease in the hysteresis occurs. As the number of bilayers in the superlattices, which contain CoFeNi alloys differing in composition increases to 12, the close values of magnetoresistance 30–31% are obtained. The correlation between the saturation magnetization of the ferromagnetic material of superlattice layers and maximum value of magnetoresistance is discussed. [ABSTRACT FROM AUTHOR]

The state of interfaces in Co/Cu superlattices with various thicknesses of non-magnetic Cu layers (tcu) has been studied by the methods of nuclear magnetic resonance (NMR) and X-ray reflectometry. The samples glass/Fe(5 nm)/[Co(1.5 nm)/Cu(tcu)]10/Cr(3 nm) were fabricated by the method of magnetron sputtering on glass substrates under constant current in the ULVAC MPS-4000-C6 device. The 59Co NMR spectra were taken in a local magnetic field in the frequency range of 90-240 MHz at 4.2 K in the pulsed NMR spectrometer. The spin echo signal was formed by a sequence of two coherent radio-frequency pulses (τp)x − tdel − (τp)y − tdel - echo forming an alternate magnetic field with the round component amplitude H1 of about 10 Oe in a resonance coil. It has been shown both by NMR and X-ray reflectometry that the structure of interfaces deteriorates with an increase of the Cu layers thickness, and similar dependences of the parameters characterizing structural imperfection of interfaces were obtained by these two methods. [ABSTRACT FROM AUTHOR]

This paper presents the results of the investigation of the structure and magnetoresistive properties of [Co90Fe10/Cu]n superlattices deposited on (Ni80Fe20)60Cr40 and Ta/(Ni80Fe20)60Cr40 buffer layers by magnetron sputtering. Our study has found that a Ta sublayer added to the (Ni80Fe20)60Cr40 buffer layer increases the degree of perfection of the 〈111〉 texture. This leads to a substantial decrease in the magnetoresistance hysteresis. The optimization of the composition of multilayered structure allowed us to obtain the superlattice with the relative magnetoresistance magnitude, which at room temperature reaches 81% and, at liquid helium temperature, exceeds 160%. The studied superlattices exhibited high temperature stability. [ABSTRACT FROM AUTHOR]

Metallic multilayer spin-valve nanostructures that comprise the exchange-coupled ferromagnet/ Ru/ferromagnet structure in the free layer have been synthesized by magnetron sputtering. For microobjects (meanders) formed from CoFe/Cu/CoFe/Ru/CoFe/FeMn/Ta spin valves with different thicknesses of ruthenium and copper layers, the dependences of the magnetoresistive sensitivity and low-field hysteresis loop shift on the meander strip width have been studied. Sensing elements characterized by high magnetoresistive sensitivity have been manufactured. [ABSTRACT FROM AUTHOR]

The influence of the interface structure on the magnetoresistive properties of Co/Cu superlattices has been studied using the techniques of nuclear magnetic resonance and X-ray reflectivity. It has been found that the roughness of interfaces and the number of cobalt atoms involved in their formation increase with annealing temperature, while the fraction of highly perfect interfaces decreases at higher temperatures. It has been demonstrated that the probability of the scattering of conduction electrons by interfaces increases with the width of these boundaries. [ABSTRACT FROM AUTHOR]