Magnetic reversal of sub-100 nm nanostructures studied by a FIB-trimmed recording head

Arrays of sub-100 nm square islands have been fabricated by patterning perpendicular Co70Cr18Pt12 continuous films using focused ion beam (FIB) lithography. The recording studies were performed on a quasi-static write/read tester using FIB trimmed recording heads with a write width of about 100 nm. We demonstrate the ability to write controlled magnetic patterns by addressing individual single-domain islands in dense island arrays achieving bit densities as high as 60 Gbit/in2 and to read back the written information. The range of write current over which single islands can be written is modeled using a write model which includes the write field distribution and the island switching field distribution. A window is found over which individual islands can be addressed without switching nearest neighbors.