Possibility of 3 Gbits/in/sup 2/ floppy disk

We tried to realize Gbits/in/sup 2/ class Floppy Disk with a magnetic layer prepared by sputtering (SP-FD). The heat-durable undercoat and the underlayers made magnetic layer have Gbits/in/sup 2/ properties, with higher S/N and narrower PW50 In comparison with those of 3.1 Gbits/in/sup 2/ HD. Heat durable substrate, fine protrusions and aerodynamics consideration allowed to achieve stable and nonaggressive contacts and good durability after running for more than 250 hours at three different environment conditions. We can conclude that the SP-FD has the potential of 3 Gbits/in/sup 2/ FD.