FePt magnet and manufacturing method thereof
AssigneeAichi Steel Corporation
InventorsHitoshi Aoyama, Yoshinobu Honkura, Takumi Asano
Life of this patent
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Abstract
The present invention offers a minute-sized magnet with superior magnetic energy product (BH)max and coercivity iHc, as well as superior anti-corrosive properties. This magnet is comprised of an alloy comprised of 35-55 atomic % platinum, 0.001-10 atomic % third element, which is one or more elements from groups IVa, Va, IIIb, or IVb, and a remainder of iron and other unavoidable impurities. The average crystal size of this FePt alloy is 0.3 μm. By mixing an FePt alloy with a specific element in a designated ratio, an FePt magnet with more excellent characteristics than ones made from previous alloys was successfully made.
Claims13
A FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities, wherein
- the alloy has an average crystal grain size of not more than 0.3 μm;
- the alloy has a CuAu (L10) face-centered tetragonal crystal structure;
- the magnet is a film between 0.1 μm and 500 μm thick;
- and
- the additional elements are one or more of elements selected from the group consisting of C, Si, Al and Zr.
A method of manufacturing a FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities,
- the method including
- a film-forming step in which the alloy is deposited as a film using a sputtering or a vacuum deposition method;
- and
- a heat-treatment step in which the alloy is heat treated so as to have a CuAu (L10) face-centered tetragonal crystal structure.
A FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities, wherein
- the alloy has an average crystal grain size of not more than 0.3 μm;
- the alloy has a CuAu (L10) face-centered tetragonal crystal structure;
- the magnet is a film between 0.1 μm and 500 μm thick;
- and
- the one or more additional elements are selected from the group consisting of IVa elements, V, Ta, Al, Ga, In, TI, and IVb elements.
A FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities, wherein
- the alloy has an average crystal grain size of not more than 0.3 μm;
- alloy has a CuAu (L10)face-centered tetragonal crystal structure;
- the magnet is a film between 0.1 μm and 500 μm thick;
- and
- the one or more additional elements are selected from the group consisting of IVa elements.
A FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities, wherein
- the alloy has an average crystal grain size of not more than 0.3 μm;
- the alloy has a CuAu (L10) face-centered tetragonal crystal structure;
- the magnet is a film between 0.1 μm and 500 μm thick;
- and
- the one or more additional elements is Zr.
A FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities, wherein
- the alloy has an average crystal grain size of not more than 0.3 μm;
- the alloy has a CuAu (L10) face-centered tetragonal crystal structure;
- the magnet is a film between 0.1 μm and 500 μm thick;
- and
- the one or more additional elements include
- at least one element selected from the group consisting of IVa elements, and
- at least one element selected from the group consisting of IIIb elements.
A FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities, wherein
- the alloy has an average crystal grain size of not more than 0.3 μm;
- the alloy has a CuAu (L10) face-centered tetragonal crystal structure;
- the magnet is a film between 0.1 μm and 500 μm thick;
- and
- the one or more additional elements include Zr and B.
A method of manufacturing a FePt magnet made of an alloy comprising
- 35-55 atomic % platinum;
- 0.001-10 atomic % of one or more additional elements selected from the group consisting of IVa, Va, IIIb and IVb elements;
- iron;
- and
- unavoidable impurities, where
- the alloy has an average crystal grain size of not more than 0.3 μm;
- the alloy has a CuAu (L10) face-centered tetragonal crystal structure;
- and
- the magnet is a film between 0.1 μm and 500 μm thick,
- the method including
- a film-forming step in which the alloy is deposited as the film using a sputtering or a vacuum deposition method;
- and
- a heat-treatment step in which the alloy is heat treated so as to have the CuAu (L10) face-centered tetragonal crystal structure.
Dependencies are inferred from the claim text.