1. A microscope, comprising:
an objective; and
a light intensity measuring unit for measuring an intensity of light emitted from the microscope, the light intensity measuring unit comprising:
an aperture stop arranged on or close to a plane corresponding to a back focal plane of the objective during observation;
a field stop arranged on or close to a plane corresponding to a front focal plane of the objective during observation;
at least one measurement lens arranged between the aperture stop and the field stop;
an interface for attachment to the microscope; and
a photodetector for measuring a light intensity,
wherein:
the field stop is positioned on or close to a front focal plane of the at least one measurement lens, and positioned between the at least one measurement lens and the photodetector;
the aperture stop is positioned on or close to a back focal plane of the at least one measurement lens; and
the light intensity measuring unit is installed in the microscope such that light equivalent to light incident on the objective during observation enters the aperture stop.
2. The microscope according to claim 1, wherein the light intensity measuring unit is provided in the microscope at a position such that an illumination unit included in the microscope is positioned between a light source unit included in the microscope and the light intensity measuring unit.
3. The microscope according to claim 2, wherein the aperture stop has a variable diameter.
4. The microscope according to claim 2, wherein the aperture stop is arranged so as to be replaceable with an aperture stop with a different diameter.
5. The microscope according to claim 3, wherein the field stop has a variable diameter.
6. The microscope according to claim 3, wherein the field stop is arranged so as to be replaceable with a field stop with a different diameter.
7. The microscope according to claim 5, wherein when \u03c6 denotes the diameter of the field stop and F denotes a total focal distance of the at least one measurement lens, a conditional expression:
1<F\u03c6<500
is satisfied.
8. The microscope according to claim 1, further comprising a recording device for recording an intensity of light detected by the photodetector.
9. The microscope according to claim 1, further comprising a control device for controlling a diameter of at least one of the aperture stop and the field stop.
10. The microscope according to claim 9, wherein the control device controls the diameter of the aperture stop so as to set the diameter of the aperture stop equal to a pupil diameter of the objective.
11. The microscope according to claim 1, wherein the light intensity measuring unit is installed in an objective nosepiece included in the microscope.
12. The microscope according to claim 1, wherein the light intensity measuring unit is installed on a mirror unit turret arranged between an objective nosepiece included in the microscope and a light source unit.
13. The microscope according to claim 12, wherein the mirror unit turret comprises:
a first mirror unit arranged thereon to guide light from the light source unit to the objective nosepiece; and
a second mirror unit arranged thereon to guide light from the light source unit to the light intensity measuring unit.
14. The microscope according to claim 1, wherein:
the light intensity measuring unit is installed in a mirror unit arranged between an objective nosepiece included in the microscope and a light source unit; and
the mirror unit splits light from the light source unit into light portions and guides one of the light portions to the objective nosepiece while guiding the other light portion to the light intensity measuring unit.
15. The microscope according to claim 1, wherein:
the microscope comprises a mirror unit turret arranged between an objective nosepiece included in the microscope and a light source unit; and
the light intensity measuring unit is installed in a mirror unit interposed between a mirror unit arranged on the mirror unit turret and the objective nosepiece.
16. The microscope according to claim 1, wherein the microscope comprises interfaces located at a plurality of positions and which are compatible with the interface.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A perpendicular magnetic recording medium comprising:
a magnetic recording layer on a nonmagnetic substrate, the magnetic recording layer comprising ferromagnetic crystal grains and nonmagnetic grain boundaries surrounding the ferromagnetic crystal grains and consisting substantially of at least two types of oxides
wherein a maximum G1 of absolute values of standard Gibbs free energy of formation per 1 mol of oxygen molecules for oxidation of ferromagnetic elements composing the ferromagnetic crystal grains, and a minimum G2 and a second smallest G3 of absolute values of standard Gibbs free energy of formation per 1 mol of oxygen molecules for oxidation of elements composing the nonmagnetic grain boundaries satisfy inequalities G1<G2<G3 and (G2-G1)>(G3-G2).
2. A perpendicular magnetic recording medium comprising:
a magnetic recording layer on a nonmagnetic substrate, the magnetic recording layer comprising ferromagnetic crystal grains and nonmagnetic grain boundaries surrounding the ferromagnetic crystal grains and consisting substantially of at least two types of nitrides
wherein a maximum G11 of absolute values of standard Gibbs free energy of formation per 1 mol of nitrogen molecules for nitridation of ferromagnetic elements composing the ferromagnetic crystal grains, a minimum G12 and a second smallest G13 of absolute values of standard Gibbs free energy of formation per 1 mol of nitrogen molecules for nitridation of elements composing the nonmagnetic grain boundaries satisfy inequalities G11<G12<G13 and (G12-G11)>(G13-G12).
3. The perpendicular magnetic recording medium according to claim 1, wherein G3-G2<200 kJmol.
4. The perpendicular magnetic recording medium according to claim 2, wherein G13-G12<200 kJmol.
5. The perpendicular magnetic recording medium according to claim 1, wherein the nonmagnetic grain boundary substantially consists of at least two types of oxides or at least two types of nitrides of elements selected from Cr, Si, Al, Ti, Ta, Hf, Zr, Y, Ce, and B.
6. The perpendicular magnetic recording medium according to claim 2, wherein the nonmagnetic grain boundary substantially consists of at least two types of oxides or at least two types of nitrides of elements selected from Cr, Si, Al, Ti, Ta, Hf, Zr, Y, Ce, and B.
7. The perpendicular magnetic recording medium according to claim 3, wherein the nonmagnetic grain boundary substantially consists of at least two types of oxides or at least two types of nitrides of elements selected from Cr, Si, Al, Ti, Ta, Hf, Zr, Y, Ce, and B.
8. The perpendicular magnetic recording medium according to claim 4, wherein the nonmagnetic grain boundary substantially consists of at least two types of oxides or at least two types of nitrides of elements selected from Cr, Si, Al, Ti, Ta, Hf, Zr, Y, Ce, and B.
9. The perpendicular magnetic recording medium according to claim 1, wherein the ferromagnetic crystal grains contain cobalt and platinum.
10. The perpendicular magnetic recording medium according to claim 2, wherein the ferromagnetic crystal grains contain cobalt and platinum.
11. The perpendicular magnetic recording medium according to claim 3, wherein the ferromagnetic crystal grains contain cobalt and platinum.
12. The perpendicular magnetic recording medium according to claim 4, wherein the ferromagnetic crystal grains contain cobalt and platinum.
13. The perpendicular magnetic recording medium according to claim 5, wherein the ferromagnetic crystal grains contain cobalt and platinum.
14. The perpendicular magnetic recording medium according to claim 1, further comprising an underlayer between the nonmagnetic substrate and the magnetic recording layer, the underlayer substantially consisting of an element selected from Ru, Rh, Os, Ir, and Pt or an alloy containing at least 50 at % of an element selected from Ru, Rh, Os, Ir, and Pt.
15. The perpendicular magnetic recording medium according to claim 14, further comprising a seed layer directly beneath the underlayer.
16. The perpendicular magnetic recording medium according to claim 2, further comprising an underlayer between the nonmagnetic substrate and the magnetic recording layer, the underlayer substantially consisting of an element selected from Ru, Rh, Os, Ir, and Pt or an alloy containing at least 50 at % of an element selected from Ru, Rh, Os, Ir, and Pt.
17. The perpendicular magnetic recording medium according to claim 16, further comprising a seed layer directly beneath the underlayer.
18. A magnetic recording device comprising the perpendicular magnetic recording medium defined by claim 1.
19. A magnetic recording device comprising the perpendicular magnetic recording medium defined by claim 2.