Abstract: Disclosed are magnetic discs having (A) a Cr-layer, as a lower layer, which has a composition comprising (1) substantially Cr or (2) 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Zr, Mo, Zn, W and Ta, and a balance of being substantially Cr, and (B) a magnetic recording medium layer, as an upper layer, which has a composition comprising (1) substantially Co, (2) 30% by weight or less of Ni and a balance of being substantially Co, (3) 10% by weight or less of one or more selected from Y, La, Ce, Pr, Nd, Sm, Gd, Tb and Dy, and a balance of being substantially Co, (4) 30% by weight or less of Ni, 10% by weight or less of one or more selected from Y, La, Ce, Pr, Nd, Sm, Gd, Tb and Dy, and a balance of being substantially Co, (5) 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Cr, Zr, Mo, Zn, W and Ta, and a balance of being substantially Co, (6) 30% by weight or less of Ni, 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Cr, Zr, Mo, Zn, W and Ta, and a balan

Abstract: A magnetic recording medium comprising a non-magnetizable substrate and a magnetic layer formed on the substrate, in which the magnetic layer comprises not more than 13% by weight of one or more of rare earth elements of Y, La, Ce, Pr, Nd, Sm, Gd, Tb or Dy, 3-13% by weight of oxygen, balance of Co and inevitable impurities. The magnetic layer may contain less than 22% by weight of Ni. The magnetic recording medium has a favorable corrosion resistance and excellent magnetic properties.

Abstract: A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed on the substrate, in which the magnetic layer comprises 1-8% metal element M consisting of one or more of B, Al, Si, P, Ge, Sn, Sb, Se, Te, Pb, Bi, Cu, Ti, V, Cr, Zr, Nb, Mo, W and Ta, less than 13% by weight of one or more of rare earth elements of Y, La, Ce, Pr, Nd, Sm, Gd, Tb, or Dy, 3-13% by weight of oxygen, balance of Co and inevitable impurities. The magnetic layer may contain less than 22% by weight of Ni. The magnetic recording medium has a favorable corrosion resistance and excellent magnetic properties.