Fabrication, writing, and reading of 10 Gbits/in² longitudinal quantized magnetic disks with a switching field over 1000 Oe

Quantized magnetic disks (QMDs) with a density of 10 Gbits/in² were fabricated using nanoimprint lithography and a lift-off process. Each bit in the QMD consists of a patterned single domain Co bar with a length of 200 nm, a width of 60 nm, and a bar spacing of 130 nm. Magnetic force microscope (MFM) was used to write and read the QMD. In 2.5 μm×2.5μm MFM window, error-free MFM writing has been achieved, even though there is no feedback control of the writing tip position and the Co bars switching field was as high as 1020 Oe.