Head slider producing reduced lubricant adsorption and magnetic storage apparatus

1. A head slider comprising:

a medium opposing surface configured to oppose a recording surface of a magnetic recording medium;

a head element provided on the medium opposing surface; and

an outlet end surface provided on a downstream side of the head element in a direction in which the magnetic recording medium moves relative to the head element, and extending substantially in a perpendicular direction from the medium opposing surface,

wherein the outlet end surface has a surface free energy greater than a surface free energy of the medium opposing surface, and

the surface free energy of the outlet end surface is higher towards an end farther away from the medium opposing surface than at an end closer to the medium opposing surface.

2. The head slider as claimed in claim 1 , wherein the surface free energy of the outlet end surface continuously increases or, increases in steps, from the end closer to the medium opposing surface towards the end farther away from the medium opposing surface.

3. The head slider as claimed in claim 1 , wherein the outlet end surface is formed by a metal layer.

4. The head slider as claimed in claim 1 , wherein the outlet end surface is formed by a carbon layer.

5. The head slider as claimed in claim 1 , wherein at least a region of the outlet end surface having a surface free energy greater than a predetermined value is formed by a metal layer.

6. A head slider comprising:

a medium opposing surface configured to oppose a recording surface of a magnetic recording medium;

a head element provided on the medium opposing surface; and

an outlet end surface provided on a downstream side of the head element in a direction in which the magnetic recording medium moves relative to the head element, and extending substantially in a perpendicular direction from the medium opposing surface, wherein

the outlet end surface has a surface free energy greater than a surface free energy of the medium opposing surface,

the outlet end surface has a first region having a first surface free energy, and a plurality of second regions each having a second surface free energy lower than the first surface free energy,

the plurality of second regions have a predetermined shape and are located in a vicinity of the medium opposing surface at predetermined positions at predetermined intervals along a direction perpendicular to said perpendicular direction, and

the predetermined shape is wider towards the end closer to the medium opposing surface and narrower towards the end farther away from the medium opposing surface.

7. The head slider as claimed in claim 6 , wherein the outlet end surface is formed by a metal layer.

8. The head slider as claimed in claim 6 , wherein the outlet end surface is formed by a carbon layer.

9. The head slider as claimed in claim 6 , wherein at least a region of the outlet end surface having a surface free energy greater than a predetermined value is formed by a metal layer.

10. A magnetic storage apparatus comprising:

a magnetic recording medium having a recording surface; and

the magnetic head slider of claim 1 .

11. The head slider as claimed in claim 10 , wherein the surface free energy of the outlet end surface is approximately three times or greater than a surface free energy of a lubricant forming a lubricant layer that is provided on the surface of the magnetic recording medium.

12. A magnetic storage apparatus comprising:

a magnetic recording medium having a recording surface; and

the magnetic head slider of claim 6 .