Magnetic media with improved exchange coupling

A magnetic disk comprising:

• a substrate;
• a lower magnetic layer structure formed over the substrate;
• an intermediate layer comprising Ru;
• an upper magnetic layer structure formed over the intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to the lower magnetic layer structure, wherein the relationship between the dynamic coercivity of the lower magnetic layer structure and the exchange field is such that during writing a portion of the lower magnetic layer structure achieves substantially its steady magnetization state within the time required for one revolution of said disk.

A magnetic disk comprising:

• a substrate;
• a lower magnetic layer structure formed over the substrate;
• an intermediate layer comprising Ru;
• and
• an upper magnetic layer structure formed over the intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to the lower magnetic layer structure, wherein the relationship between the dynamic coercivity of the lower magnetic layer structure and the exchange field is such that during writing a portion of the lower magnetic layer structure achieves more than 90% of its steady magnetization state within the time required for one revolution of said disk.

A magnetic disk comprising:

• a substrate;
• a lower magnetic layer structure formed over the substrate;
• an intermediate layer comprising Ru;
• and
• an upper magnetic layer structure formed over the intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to the lower magnetic layer structure, wherein the relationship between the dynamic coercivity of the lower magnetic layer structure and the exchange field is such that during writing a portion of the lower magnetic layer structure achieves more than 95% of its steady magnetization state within the time required for one revolution of said disk.

A magnetic recording medium comprising:

• a substrate;
• a lower magnetic layer structure formed over the substrate;
• an intermediate layer comprising Ru;
• and
• an upper magnetic layer structure formed over the intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to the lower magnetic layer structure, wherein the relationship between the dynamic coercivity of the lower magnetic layer structure and the exchange field is such that during writing a portion of the lower magnetic layer structure achieves substantially its steady magnetization state within 100 milliseconds.

A magnetic recording medium comprising:

• a substrate;
• a lower magnetic layer structure formed over the substrate;
• an intermediate layer comprising Ru;
• and
• an upper magnetic layer structure formed over the intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to the lower magnetic layer structure, wherein the relationship between the dynamic coercivity of the lower magnetic layer structure and the exchange field is such that during writing a portion of the lower magnetic layer structure achieves more than 90% of its steady magnetization state within 100 milliseconds.

A magnetic recording medium comprising:

• a substrate;
• a lower magnetic layer structure formed over the substrate;
• an intermediate layer comprising Ru;
• and
• an upper magnetic layer structure formed over the intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to the lower magnetic layer structure, wherein the relationship between the dynamic coercivity of the lower magnetic layer structure and the exchange field is such that during writing a portion of the lower magnetic layer structure achieves more than 95% of its steady magnetization state within 100 milliseconds.

Magnetic recording medium comprising:

• a substrate;
• a lower magnetic layer structure formed over said substrate, said lower magnetic layer structure having a Ku between 0 and 106 erg/cm3;
• an intermediate layer comprising Ru formed over the lower magnetic layer structure;
• and
• an upper magnetic layer structure formed over said intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to said lower magnetic layer structure and having a Ku greater than 106 erg/cm3.

A magnetic recording medium comprising:

• a lower magnetic layer structure;
• an intermediate layer comprising Ru formed over the lower magnetic layer structure;
• and
• an upper magnetic layer structure antiferromagnetically coupled to the lower magnetic layer structure and formed over said intermediate layer, the dynamic coercivity of the lower magnetic layer structure being greater than or equal to zero but less than the exchange field between the upper and lower magnetic layer structures.

Magnetic recording medium comprising:

• a substrate;
• a lower magnetic layer structure formed over said substrate;
• an intermediate layer comprising Ru formed over said lower magnetic layer;
• and
• an upper magnetic layer structure formed over said intermediate layer, said upper magnetic layer being antiferromagnetically coupled to said lower magnetic layer structure, the coercivity of said lower magnetic layer structure as measured in a switching time of 10 milliseconds being less than the exchange field between said upper and lower magnetic layer structures.

Magnetic recording medium comprising:

• a substrate;
• a lower magnetic structure formed over said substrate, said lower magnetic structure comprising a magnetically soft material with intergranular decoupling;
• an intermediate layer comprising Ru formed over said lower magnetic layer structure;
• and
• an upper magnetic layer structure formed over said intermediate layer, said upper magnetic layer structure being antiferromagnetically coupled to said lower magnetic layer structure.