Compositional and magnetic properties of iron nitride thin films

The compositional and magnetic properties of iron-nitride thin films deposited by de reactive magnetron sputtering under various nitrogen partial pressure conditions have been investigated by x-ray diffraction, Mossbauer and Auger electron spectroscopy as wen as magnetic measurements. The x-ray diffraction patterns indicate a mixed phase composition. 57Fe Mossbauer spectroscopy shows that part of the nitrogen atoms are randomly distributed on interstitial sites with the formation of nonstoichiometric compounds. The excessive width of the Mossbauer lines indicates the degree of disorder of the different iron nitride precipitates. The nitrogen concentration as a function of depth is obtained by sputter-etched Auger electron spectroscopy. Furthermore, the ferromagnetic films show moderate saturation magnetization and coercivities at room temperature as compared with pure iron thin films

Epitaxial fe/cu superlattices on Si(111)

We report on the successful epitaxial growth of Fe/Cu superlattices on Si( 111) wafers at room temperature. The superlattices were characterized with x-ray diffraction, conversion electron Mossbauer spectrometry, and selected area electron diffraction experiments. The epitaxial growth is crucially dependent on which element is deposited first on the bare Si( 111)

Compositional and magnetic properties of iron nitride thin films

The compositional and magnetic properties of iron-nitride thin films deposited by de reactive magnetron sputtering under various nitrogen partial pressure conditions have been investigated by x-ray diffraction, Mossbauer and Auger electron spectroscopy as wen as magnetic measurements. The x-ray diffraction patterns indicate a mixed phase composition. 57Fe Mossbauer spectroscopy shows that part of the nitrogen atoms are randomly distributed on interstitial sites with the formation of nonstoichiometric compounds. The excessive width of the Mossbauer lines indicates the degree of disorder of the different iron nitride precipitates. The nitrogen concentration as a function of depth is obtained by sputter-etched Auger electron spectroscopy. Furthermore, the ferromagnetic films show moderate saturation magnetization and coercivities at room temperature as compared with pure iron thin films

Oscillatory interlayer exchange and magnetoresistance in Fe/Cu multilayers

We have studied the magnetic and magnetotransport properties of Fe/Cu mu1tilayers prepared by sputtering. We find oscillations of the inter1ayer coupling as a function of the Cu thickness with the same long period as in Co/Cu multilayers (around 12.5 Á). The most striking result is that the oscillations in Fe/Cu and Co/Cu have almost exactly opposite phases. A large magnetoresistance of the spin-valve type is observed in the half periods with antiferromagnetic interlayer exchange. However, the magnetoresistance in Fe/Cu is definitely smaller than in Co/Cu

The epitaxial growth of evaporated cu/caf2 bilayers on si(111)

Successful and unexpected epitaxial growth of Cu/CaF2, bilayers on hydrogen terminated Si(111) wafers by thermal evaporation is reported. The bilayers were characterized with conventional x-ray diffraction experiments, grazing angle incidence x-ray diffraction experiments, rocking curves, and x scans. The growth mode of Cu films on CaF2 epitaxially grown on Si(111) is completely different from that of the Cu film grown directly on Si(111)

The evolution of sputtered iron nitride thin films under thermal treatment

The thermal evolution of reactively sputtered iron nitride thin films has been investigated by xray diffraction, Mössbauer conversion electron spectroscopy, transmission electron microscopy, and magnetic measurementsT. he results show that, independentlyo f the original nitrogen content of the films, a similar composition of the end products after the 500 °C annealings is reached, being all composed of α-Fe plus y-Fe4 N in a wide range of relative proportions. The magnetic characteristics, however, are different depending on the nitrogen content of the as-depositedf ilms

The evolution of sputtered iron nitride thin films under thermal treatment

The thermal evolution of reactively sputtered iron nitride thin films has been investigated by xray diffraction, Mössbauer conversion electron spectroscopy, transmission electron microscopy, and magnetic measurementsT. he results show that, independentlyo f the original nitrogen content of the films, a similar composition of the end products after the 500 °C annealings is reached, being all composed of α-Fe plus y-Fe4 N in a wide range of relative proportions. The magnetic characteristics, however, are different depending on the nitrogen content of the as-depositedf ilms

La Voz de Asturias : diario de información: Año XI Número 3300 - 1933 Noviembre 14

In this work we present low-field magnetic measurements on multilayers of Fe 1.5 nm and Cu 1.5 nm layers, repeated 10 times, grown on Si~111! and Fe 5 nm/CaF2 40 nm/Si(111), substrates. Magnetic characteristics of a spin-glass phase are exhibited by samples directly grown on Si (111), for which the glass temperatures (TG) depend strongly on the magnetic field. Above TG those samples exhibit a ferromagnetic behavior. In contrast, samples grown on Fe/CaF2 buffer structure also show the spin-glass characteristics, but are antiferromagnetic above TG . This work deals with the fundamental role played by the interface between Fe and Cu for these effects, which is clearly emphasized by the experimental results

Oscillatory interlayer exchange and magnetoresistance in Fe/Cu multilayers

We have studied the magnetic and magnetotransport properties of Fe/Cu mu1tilayers prepared by sputtering. We find oscillations of the inter1ayer coupling as a function of the Cu thickness with the same long period as in Co/Cu multilayers (around 12.5 Á). The most striking result is that the oscillations in Fe/Cu and Co/Cu have almost exactly opposite phases. A large magnetoresistance of the spin-valve type is observed in the half periods with antiferromagnetic interlayer exchange. However, the magnetoresistance in Fe/Cu is definitely smaller than in Co/Cu