Interactions and switching field distributions of nanoscale magnetic elements

Magnetic nano-elements made from NiFe and Co have been investigated using m agnetic imaging in the transmission electron microscope. Nano-elements like these have possible uses for in-plane patterned media or solid state memor y. In both cases the elements will need to be patterned into closely spaced arrays and magnetostatic interactions between the elements will begin to b ecome significant. Arrays must therefore be designed so that an element's i nteractions with its neighbors will be small compared to its coercivity. Ar rays of NiFe elements 300 nm long, 50-100 nm wide, and 26 nm thick, were fa bricated by electron beam lithography and lift-off patterning. Their switch ing behavior and the interactions between them were studied in detail. Magn etization sequences were recorded and hysteresis loops constructed. For row s of NiFe elements with the gap between elements the same as the element wi dth or larger, the interactions turn out to be small, suggesting that dense r arrays would be possible. (C) 2000 American Institute of Physics. [S0021- 8979(00)37008-6].