Co layer fragmentation effect on magnetoresistive and structural properties of nanogranular Co/Cu multilayers

Journal Article · Mon Jun 15 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3151690· OSTI ID:21352257

Spizzo, F; Ronconi, F ^[1]; Ferrero, C; Mazuelas, A; Metzger, T H ^[2]; Albertini, F; Casoli, F; Nasi, L ^[3]

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1. Dipartimento di Fisica and CNISM, Polo Scientifico e Tecnologico, Universita degli Studi di Ferrara, via Saragat, 1 I-44100 Ferrara (Italy)
2. ESRF, BP 220, F-38043 Grenoble (France)
3. IMEM-CNR, Parco Area delle Scienze, 37/A I-43100 Parma (Italy)

We deposited nanogranular Co/Cu multilayers made of thin fragmented Co layers separated by thicker Cu layers to study how the structure and the microstructure of magnetic nanogranular samples change as the average particle size is reduced and how these changes affect the giant magnetoresistive response of the samples. Indeed, thanks to the vertical periodicity of the structure, namely, to the fact that Co/Cu interfaces display an ordered stacking and are not randomly distributed within the samples as in conventional granular materials, their self-correlation and cross correlation can be investigated. In this way, the characteristic length scale of the Co/Cu interfacial roughness that is strictly related to the giant magnetoresistive response of the samples and the universality class of the growth mechanism that affects the systems structure can be both accessed. The Co/Cu nanogranular multilayers were characterized using different x-ray techniques, from specular reflectivity, which allows to probe the multilayer development in the vertical direction, to grazing incidence small angle diffuse scattering, which provides information on the self-correlation and cross correlation of the Co/Cu interfaces. Furthermore, diffraction measurements indicate that the degree of structural disorder increases by decreasing the thickness of the Co layers. Magnetoresistive and magnetization measurements are as well presented and discussed with the results of the structural characterization.

• OSTI ID: 21352257
• Journal Information: Journal of Applied Physics, Vol. 105, Issue 12; Other Information: DOI: 10.1063/1.3151690; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT
COPPER
CORRELATIONS
CRYSTAL GROWTH
CRYSTAL STRUCTURE
DIFFUSE SCATTERING
FRAGMENTATION
GRANULAR MATERIALS
LAYERS
MAGNETIZATION
MAGNETORESISTANCE
MICROSTRUCTURE
NANOSTRUCTURES
PARTICLE SIZE
PERIODICITY
REFLECTIVITY
ROUGHNESS
THIN FILMS
COHERENT SCATTERING
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
MATERIALS
METALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SCATTERING
SIZE
SURFACE PROPERTIES
TRANSITION ELEMENTS
VARIATIONS