US 7,842,408 B2 · Magnetic film, manufacturing method thereof and thin film magnetic head

Abstract

Embodiments of the present invention provide a magnetic disk drive capable of allowing higher data transfer rates and higher recording densities. According to one embodiment, an upper magnetic core and lower magnetic core comprise a multi-layered magnetic film formed by alternately stacking a face-centered cubic (fcc) crystalline magnetic thin layer and a body-centered cubic (bcc) crystalline magnetic thin layer by plating. The plating bath is such that the temperature is about 30±1° C., pH is about 2.0−1.0 to 2.0+0.5, metal ion concentrations are about 5 to 25 (g/l) for Ni2+ and 5 to 15 (g/l) for Fe2+, saccharin sodium concentration is about 1.5±1.0 (g/l), sodium chloride concentration is about 25±5 (g/l), and boric acid concentration is about 25±5 (g/l). Since each layer's crystal structure is different from that of its adjacent lower layer, epitaxial growth is broken within each layer. Thus, since crystal grains are reduced in size, it is possible to lessen the decrease of the permeability μ at higher frequencies.

Claims9

Dependent claims

A magnetic film comprising a multi-layered magnetic film which is formed by a body-centered cubic crystalline magnetic plated thin layer and a face-centered cubic crystalline magnetic plated thin layer;

wherein the thickness of the body-centered cubic crystalline magnetic plated thin layer is larger than the thickness of the face-centered cubic crystalline magnetic plated thin layer;
wherein the body-centered cubic crystalline magnetic plated thin layer and the face-centered cubic crystalline magnetic plated thin layer are 0.5 to 20 nm in thickness;
wherein each layer of the multi-layered magnetic film has a different crystal structure from an immediately adjacent layer and epitaxial growth of each layer is broken by the immediately adjacent layer such that crystal grains of each layer are not larger than the thickness of their respective layer, and
wherein the multi-layered magnetic film has at least four layers total of the body-centered cubic crystalline magnetic plated thin layer and the face-centered cubic crystalline magnetic plated thin layer alternately and sequentially stacked.

1 more element

A thin film magnetic head comprising:

a read head;
and
a write head which is located adjacent to the read head and has plural magnetic films;
wherein at least one of the plural magnetic films constituting the write head comprises a multi-layered magnetic film which is fabricated by a body-centered cubic crystalline magnetic plated thin layer and a face-centered cubic crystalline magnetic plated thin layer;
wherein the thickness of the body-centered cubic crystalline magnetic plated thin layer is larger than the thickness of the face-centered cubic crystalline magnetic plated thin layer;
wherein either the body-centered cubic crystalline magnetic plated thin layer or the face-centered cubic crystalline magnetic plated thin layer are 0.5 to 20 nm in thickness
wherein each layer of the multi-layered magnetic film has a different crystal structure from an immediately adjacent layer and epitaxial growth of each layer is broken by the immediately adjacent layer such that crystal grains of each layer are not larger than the thickness of their respective layer, and
wherein the multi-layered magnetic film has at least four layers total of the body-centered cubic crystalline magnetic plated thin layer and the face-centered cubic crystalline magnetic plated thin layer alternately and sequentially stacked.

5 more elements

Dependencies are inferred from the claim text.

Magnetic film, manufacturing method thereof and thin film magnetic head

Life of this patent

Magnetic film, manufacturing method thereof and thin film magnetic head

Life of this patent

Abstract

Claims9