Modified equations have been derived on the basis of Makishima-Machenzie (M
..M) theory for direct determination of the elastic modulus of glasses from
composition, This modified calculation model gives an excellent agreement
between the measured and estimated values of elastic modulus for over 50 di
fferent glasses, Using this model we developed a glass in the Li2O-MgO-Al2O
3-Y2O3-TiO2-SiO2 system with elastic modulus value greater than 130 GPa and
bending strength higher than 50 kg f/mm(2). This high modulus glass substr
ate is expected to provide a solution to the vibration problem of rapid rot
ation magnetic disk and allow higher track density per inch to be achieved
for high performance hard-disk drives (HDDs). (C) 2001 Elsevier Science B.V
, All rights reserved.