Magnetostatic Fields in Multilayer Composite Films with a Bimodal Granule Size Distribution

Authors I.G. Shipkova , Yu.I. Veretennikova, H.A. Kholodov

National Technical University «Kharkiv Polytechnic Institute», 2, Kyrpychova St., 61002 Kharkiv, Ukraine

Issue Volume 13, Year 2021, Number 4
Dates Received 19 March 2021; revised manuscript received 06 August 2021; published online 20 August 2021
Citation I.G. Shipkova, Yu.I. Veretennikova, H.A. Kholodov, J. Nano- Electron. Phys. 13 No 4, 04010 (2021)
PACS Number(s) 75.75. – с, 75.70.Сn
Keywords Composite (45) , Multilayer nanostructure, Magnetic dipole, Internal field, Numerical calculations.

Numerical calculations of internal fields in multilayer nanostructures composed of magnetic composite layers and nonmagnetic interlayers were carried out. Systems with bimodal granule size distribution were examined. Models of such systems were formed by rearrangement and coalescence of granules inside each layer of a monomodal regular structure while maintaining magnetic particle volume concentration. Magnetic fields at the positions of certain granules were calculated as the vector sum of the dipole fields generated by all the granules in the system. Model parameters corresponded to the characteristics of real multilayer composite nanostructures with a magnetic phase content below the percolation threshold. Thus, for a composite with a granule magnetization of 1250 G, the content of the magnetic phase in the layers was chosen equal to 13 vol. %. Small particles were 3 nm in size. The calculations were carried out for a different number of particle positions in the system (102-107), and it was found that the results of calculations after exceeding the number of points ( 105 practically do not change. The intervals between the values of local fields at various layer points were determined depending on the nonmagnetic interlayer thickness (from 2 to 4 nm). It was shown that the difference in the values of local dipole fields in a system with the considered bimodal distribution of granules might amount to 1500 Oe.

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