Magnetic recording medium, method of manufacturing same, and magnetic recording and reproducing apparatus
A magnetic recording medium includes a non-magnetic substrate; a soft magnetic layer; a first seed layer; a second seed layer; an underlayer; and a perpendicular magnetic recording layer. The soft magnetic layer, the first seed layer, the second seed layer, the underlayer and the perpendicular magnetic recording layer are disposed on the non-magnetic substrate in this order. The first seed layer includes MoS 2 , hexagonal-BN, WS 2 , WSe 2 or graphite. The second seed layer includes AlN having a hexagonal wurtzite type crystal structure. The underlayer includes Ru.
1. A magnetic recording medium comprising:
a non-magnetic substrate;
a soft magnetic layer;
a first seed layer;
a second seed layer;
an underlayer; and
a perpendicular magnetic recording layer,
wherein the soft magnetic layer, the first seed layer, the second seed layer, the underlayer and the perpendicular magnetic recording layer are disposed on the non-magnetic substrate in this order,
wherein the first seed layer includes, as a main component, MoS 2 , WS 2 , WSe 2 or graphite,
wherein the second seed layer includes, as a main component, AlN having a hexagonal wurtzite type crystal structure,
wherein the underlayer includes Ru, and
wherein the second seed layer is directly deposited on the first seed layer by a reactive sputtering method using a pulse voltage or by a reactive sputtering method using hollow cathode plasma.
2. The magnetic recording medium according to claim 1 , wherein the second seed layer has an average crystal grain size within a range of 3 nm to 12 nm.
3. The magnetic recording medium according to claim 1 , wherein the second seed layer has a thickness within a range from 0.5 nm to 20 nm.
4. The magnetic recording medium according to claim 1 , wherein the soft magnetic layer has an amorphous structure.
5. A method of manufacturing the magnetic recording medium according to claim 1 , the method comprising:
depositing the second seed layer by the reactive sputtering method using a pulse voltage,
wherein, when depositing the second seed layer, the pulse voltage is less than or equal to −300 V, a pulse current is greater than or equal to 10 A, a duty cycle is less than or equal to 10%, Al is used as a target, and nitrogen is used as a sputtering gas.
6. A method of manufacturing the magnetic recording medium according to claim 1 ,
depositing the second seed layer by the reactive sputtering method using hollow cathode plasma,
wherein, when depositing the second seed layer, Al is used as a target, and nitrogen is used as a sputtering gas.
7. A magnetic recording and reproducing apparatus comprising:
the magnetic recording medium according to claim 1 .