| 摘要 |
PROBLEM TO BE SOLVED: To reduce the so-called popcorn noise which is a spike-like random noise component appearing in a reproduction output immediately after a recording operation by forming an upper magnetic shielding layer comprising a first magnetic shielding layer, with a thickness in a specific range, close to a magneto-resistance effect sensor for reproduction and a second magnetic shielding layer deposited onto the first magnetic shielding layer. SOLUTION: An upper magnetic shielding layer 16 is composed of a portion (underlying film) 16a (first magnetic shielding layer) close to an MR sensor section 14 and the other portion (upper magnetic shielding layer portion) 16b (second magnetic shielding layer) than the underlying film 16a of the upper magnetic shielding layer 16, and the thickness of the underlying film 16a is in the range from 0.1μm to 1.0μm. Permalloy containing nickel(Ni) and iron as its main components is used as the underlying film 16a, and the underlying film 16a is deposited by sputtering to achieve a desired thickness and magnetostriction constant. It is desirable that the composition of Ni in the underlying film 16a is in the range from 81.5% to 85% and the magnetostriction constant of the underlying film 16a is in the range from 0 to -5×10-6.
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