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arXiv · 0704.3970

A study of uranium-based multilayers: II. Magnetic properties

R Springell·S W Zochowski·R C C Ward·M R Wells·S D Brown·L Bouchenoire·F Wilhelm·S Langridge·W G Stirling·G H Lander
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Abstract

SQUID magnetometry and polarised neutron reflectivity measurements have been employed to characterise the magnetic properties of U/Fe, U/Co and U/Gd multilayers. The field dependence of the magnetisation was measured at 10K in magnetic fields from -70kOe to 70kOe. A temperature dependent study of the magnetisation evolution was undertaken for a selection of U/Gd samples. PNR was carried out in a field of 4.4kOe for U/Fe and U/Co samples (at room temperature) and for U/Gd samples (at 10K). Magnetic 'dead' layers of about 15 Angstrom were observed for U/Fe and U/Co samples, consistent with a picture of interdiffused interfaces. A large reduction in the magnetic moment, constant over a wide range of Gd layer thicknesses, was found for the U/Gd system (about 4 Bohr magnetons compared with 7.63 for the bulk metal). This could be understood on the basis of a pinning of Gd moments arising from a column-like growth mechanism of the Gd layers. A study of the effective anisotropy suggests that perpendicular magnetic anisotropy could occur in multilayers consisting of thick U and thin Gd layers. A reduction in the Curie temperature was observed as a function of Gd layer thickness, consistent with a finite-size scaling behaviour.

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R Springell, S W Zochowski, R C C Ward, M R Wells, S D Brown, L Bouchenoire, F Wilhelm, S Langridge, W G Stirling, G H Lander. 2007-04-30. A study of uranium-based multilayers: II. Magnetic properties. https://doi.org/10.1088/0953-8984%2F20%2F21%2F215230

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