Abstract: There is disclosed an improved memory disk stock comprised of an alloy composition which includes: about 1-11 wt. % magnesium, preferably between about 2-7 wt. % Mg; up to about 0.3 wt. % zirconium, preferably about 0.02-0.25 wt. % Zr; up to about 0.2 wt. % iron, up to about 0.2 wt. % silicon, and about 0.05-1 wt. % of a dispersoid-forming element selected from scandium, erbium, thulium, lutetium, ytterbium, hafnium and yttrium, the balance aluminum and incidental elements and impurities. With preferably about 0.1-0.45 wt. % of scandium added to such compositions, these disk stocks exhibit a two- to three-fold increase in strength over the same compositions without any scandium added. They result in magnetic media recording devices having improved temperature resistance with average yield strengths of 30 ksi or more. There is also claimed an improved method for making such memory disk devices.