Abstract
We evaluated the effects of inter-bit material on the switching performance of bit patterned media (BPM) fabricated by direct deposition of magnetic material onto pre-patterned substrates. We performed a controlled experiment to vary the sidewall thickness and symmetry in bits with nominally identical size and pitch. Thick, asymmetric sidewalls resulted in significant broadening of the switching field distribution to 14%-20% compared to 10%-11% for bits with thin, symmetric sidewalls. These differences were attributed to changes in the intrinsic properties and dipolar interactions as supported by micromagnetic simulations. Our results highlight the importance of controlling inter-bit material to achieve high-density BPM. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4758478]