Patent ID: 6979501

Claim:
A magnetic recording medium comprising a biaxially tensilized substrate having a front side and a backside, a longitudinal direction and a crossweb direction, said substrate having a magnetic layer formed over said front side of said substrate comprising magnetic pigment particles, and a binder system therefor; said magnetic recording medium having a cross web dimensional difference from a substrate wafer of an Al 2 O 3 —TiC bi-phase ceramic formed from aluminum oxide and titanium carbide of less than 900 microns/meter over a temperature range of about 35 degrees, and over a relative humidity range of about 70%, and a coefficient of thermal expansion having a value said magnetic recording medium having a coefficient of thermal expansion of from about 5 ppm/C to about 10 ppm/C, said coefficient of thermal expansion being from about 50% to about 150% of the coefficient of thermal expansion for the substrate wafer.