Low profile multidentate lubricants for use at sub-nanometer thicknesses in magnetic media

1. A lubricant, comprising:

a multidentate perfluoropolyether having the formula:

S e -S o -S i -S L -S i -S o -S e ,

wherein each S o segment has a molecular structure according to formula (8)

—OCH 2 CF 2 O—(CF 2 CF 2 O) n —CF 2 CH 2 O—,   (8)

wherein n for each S o segment is an integer ranging from 1 to 10;

wherein S L has a molecular structure according to formula (9):

—OCH 2 CH 2 O—  (9),

wherein S e and S i each includes at least one functional group configured to attach to a surface, wherein the at least one functional group is selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a carboxylic acid, a phosphazene group, and combinations thereof.

2. The lubricant as recited in claim 1 , wherein each S e comprises at least two functional groups configured to attach to a surface, the at least two functional groups being independently selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a carboxylic acid, a phosphazene group, and combinations thereof.

3. The lubricant as recited in claim 1 , wherein each S i comprises one functional group configured to attach to a surface, the functional group being selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a phosphazene group, and combinations thereof.

4. The lubricant as recited in claim 1 , wherein the multidentate perfluoropolyether includes six functional groups configured to attach to a surface.

5. The lubricant as recited in claim 4 , wherein the six functional groups are hydroxyl groups.

6. A magnetic medium, comprising:

a magnetic recording layer positioned above a non-magnetic substrate;

a protective overcoat positioned above the magnetic recording layer; and

a lubricant layer comprising the lubricant as recited in claim 1 .

7. The magnetic medium as recited in claim 6 , wherein a thickness of the lubricant layer is between 7 Å to 8 Å, and wherein the multidentate perfluoropolyether exhibits a bonded percentage of at least 75%.

8. A magnetic data storage system, comprising:

at least one magnetic head;

the magnetic recording medium as recited in claim 6 ;

a drive mechanism for passing the magnetic recording medium over the at least one magnetic head; and

a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

9. A lubricant, comprising:

a multidentate perfluoropolyether having the formula:

S e -S o(a) -S i -S m -S i -S o(b) -S e ,

wherein S o(a) has a molecular structure according to formula (16):

—OCH 2 CF 2 O—(CF 2 CF 2 O) n —CF 2 CH 2 O—  (16),

S o(b) has a molecular structure according to formula (17):

—OCH 2 CF 2 O—(CF 2 CF 2 O) y —CF 2 CH 2 O—  (17),

S m comprises a molecular structure according to formula 18:

—(CF 2 CF 2 O) k —  (18),

wherein each of n, y and k is independently an integer greater than zero and k is different than at least one of n and y,

wherein S e and S i each includes at least one functional group configured to attach to a surface, wherein the at least one functional group is selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a carboxylic acid, a phosphazene group, and combinations thereof.

10. The lubricant as recited in claim 9 , wherein k is less than at least one of n and y.

11. The lubricant as recited in claim 9 , wherein k is greater than at least one of n and y.

12. The lubricant as recited in claim 9 , wherein the multidentate perfluoropolyether includes eight functional groups configured to attach to a surface.

13. The lubricant as recited in claim 12 , wherein the eight functional groups are hydroxyl groups.

14. A magnetic recording medium, comprising:

a magnetic recording layer positioned above a non-magnetic substrate;

a protective overcoat positioned above the magnetic recording layer; and

a lubricant layer comprising the lubricant as recited in claim 9 .

15. The magnetic medium as recited in claim 14 , wherein a thickness of the lubricant layer is between 7 Å to 8 Å, and wherein the multidentate perfluoropolyether exhibits a bonded percentage of at least 75%.

16. A magnetic data storage system, comprising:

at least one magnetic head;

the magnetic recording medium as recited in claim 14 ;

a drive mechanism for passing the magnetic recording medium over the at least one magnetic head; and

a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

17. The lubricant of claim 1 , wherein each S e segment has a molecular structure according to formula (10):

wherein each X is independently selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a phosphazene group, and combinations thereof.

18. The lubricant of claim 1 , wherein each S i segment is selected from molecular structures having formulas (11) and (12):

wherein each X is independently selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a phosphazene group, and combinations thereof.

19. The lubricant of claim 1 , wherein

each S e segment has a molecular structure according to formula (10):

and

each S i segment is selected from molecular structures having formulas (11) and (12):

wherein each X is independently selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a phosphazene group, and combinations thereof.

20. The lubricant of claim 1 having an average MW in a range from about 1000 amu to about 6000 amu.

21. The lubricant of claim 1 having the molecular formula:

CH 2 (OH)CH(OH)CH 2 OCH 2 CF 2 O(CF 2 CF 2 O) n CF 2 CH 2 OCH 2 CH(OH)CH 2 CH 2 OCH 2 CH 2 OCH(O H)CH 2 OCH 2 CF 2 O(CF 2 CF 2 O) n CF 2 CH 2 OCH 2 CH(OH)CH 2 (OH), wherein n is an integer greater than or equal to 2.

22. The lubricant of claim 9 , wherein each S e segment has a molecular structure according to formula (19):

wherein each X is independently selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a phosphazene group, and combinations thereof.

23. The lubricant of claim 9 , wherein each S i segment is selected from molecular structures having formulas (20) and (21):

wherein each X is independently selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a phosphazene group, and combinations thereof.

24. The lubricant of claim 9 , wherein each S e segment has a molecular structure according to formula (19):

and each S i segment is selected from molecular structures having formulas (20) and (21):

wherein each X is independently selected from the group consisting of: a hydroxyl group, a piperonyl group, an amine group, a phosphazene group, and combinations thereof.

25. The lubricant of claim 9 having an average MW in a range from about 1000 amu to about 6000 amu.

26. The lubricant of claim 9 having the molecular formula CH 2 (OH)CH(OH)CH 2 OCH 2 CF 2 O(CF 2 CF 2 O) n CF 2 CH 2 OCH 2 CH(OH)CH 2 OCH 2 CH(OH) CH 2 OCH 2 CF 2 O(CF 2 CF 2 O) k CF 2 CH 2 OCH(OH)CH 2 OCH 2 CH(OH)CH 2 OCH 2 CF 2 O(CF 2 CF 2 O) y CF 2 CH 2 OCH 2 CH(OH)CH 2 (OH),

wherein n, k and y are each independently an integer greater than one with the proviso that k is different than at least one of n and y.