| 摘要 |
PURPOSE:To enable the intensity of a magnetic field easily varied by providing a shield member with which a magnetic field of an objective lens, which is leaked out due to a magnetic saturation caused when the excitation of the objective lens is increased, is applied to a sample. CONSTITUTION:A lower magnetic pole 5b, which is provided with a penetration hole 9 perpendicular to an optical axis 8, is situated so that it faces to an upper magnetic pole 5a of an objective lens 4. A thin magnetic sample 11 attached to a side-entry-type sample holder 10 is located within the hole 9. In addition, the thickness of the upper part (M) of the hole 9 of the lower magnetic pole 5b is adjusted so that a magnetic saturation occurs when the excitation current of the lens 4 becomes above a given value, and so that a magnetic field vertical to the surface of the sample 11 is applied to the sample 11 due to the leakage of a main magnetic field. As a result, the intensity of the magnetic field vertical to the sample surface can be easily varied by changing the current fed to an excitation coil 6, without mechanically moving the sample 11. |
