Calculations and measurements of the magnetic field of patterned permanent magnetic films for lab-on-chip applications
Résumé
The growing research in the applications of magnetically patterned thin film permanent magnets (PM) for lab-on-chip micromanipulation of various microscopic objects and for microelectro- mechanical systems (MEMS) increases the demand for characterization of the magnetic space field distribution produced by such PMs. In the present work calculations are made for different patterns and magnetization distributions of Nd-Fe-B anisotropic films deposited onto 100 mm Si substrates using high rate triode sputtering. Space resolved magnetic imaging techniques utilizing magneto-optical indicator films (MOIF) were applied for the visualization of the magnetic field microdistribution with a resolution of the order of 1 micrometer. Both uniaxial and planar MOIF calibrated with the aid of a known external field were used to achieve quantitative measurements. Deviation of the data measured for real samples from the results of calculations performed for the idealized case of a uniform material are revealed. The obtained results are used both for the characterization of the performance of corresponding devices and for the correction of technological parameters of film preparation.