Japan Science and Technology Agency

University of Chicago

Wei Zhang

Akihisa Inoue

Akihiro Makino

Hisamichi Kimura

Hisashi Yamamoto

Arindrajit Basak

Tao Zhang

A magnetic recording medium 1 includes a substrate 11; and a metallic glassy layer 12 that is arranged on the substrate 11 and has a plurality of convex portions 12A and concave portions 12B. The metallic glassy layer 12 has a chemical composition represented by any one of the formulae (1) to (3):FePtSiBP(wherein, 20&#x3c;m&#x2266;60 at %, 20&#x3c;n&#x2266;55 at %, 11&#x2266;x&#x3c;19 at %, 0&#x2266;y&#x3c;8 at %, and 0&#x3c;z&#x3c;8 at %)&#x2003;&#x2003;(1);FePt(SiBP)(wherein, 11&#x2266;x&#x3c;19 at %, 0&#x2266;y&#x3c;8 at %, and0 &#x3c;z&#x3c;8 at %)&#x2003;&#x2003;(2); and(FePtSiBP)-M(wherein, 0&#x3c;X&#x2266;6 at %; and M represents an element or a combination of any two or more of the elements selected from Zr, Nb, Ta, Hf, Ti, Mo, W, V, Cr, Mn, Al, Y, Ag,and rare earth elements.)&#x2003;&#x2003;(3).

Metallic glass, magnetic recording medium using the same, and method of manufacturing the magnetic recording medium

The present invention provides Cu-base amorphous alloys containing an amorphous phase of 90% or more by volume fraction. The amorphous phase has a composition represented by the formula: Cu(Zr+Hf)Tior Cu(Zr+Hf')TiMT, wherein M is one or more elements selected from Fe, Cr, Mn, Ni, Co, Nb, Mo, W, Sn, Al, Ta and rare earth elements, T is one or more elements selected from the group consisting of Ag, Pd, Pt and Au, and a, b, c and d are atomic percentages falling within the following ranges: 5&#x2266;a&#x2266;55, 0&#x2266;b&#x2266;45, 30&#x2266;a+b&#x2266;60, 0.5&#x2266;c&#x2266;5, 0&#x2266;d&#x2266;10. The Cu-base amorphous alloy has a high glass-forming ability as well as excellent mechanical properties and formability, and can be formed as a rod or plate material with a diameter or thickness of 1 mm or more and an amorphous phase of 90% or more by volume fraction, through a metal mold casting process.

Method of making a Cu-base bulk amorphous alloy

A magnetic recording mediumincludes a substrate; and a metallic glassy layerthat is arranged on the substrateand has a plurality of convex portionsA and concave portionsB. The metallic glassy layerhas a chemical composition represented by any one of the formulae (1) to (3): FePtSiBP(wherein, 20&#x3c;m&#x2266;60 at %, 20&#x3c;n&#x2266;55 at %, 11&#x2266;x&#x3c;19 at %, 0&#x2266;y&#x3c;8 at %, and 0&#x3c;z&#x3c;8 at %) (1); FePt(SiBP)(wherein, 11&#x2266;x&#x3c;19 at %, 0&#x2266;y&#x3c;8 at %, and 0&#x3c;z&#x3c;8 at %) (2); and (FePtSiBP)M(wherein 0&#x3c;X&#x2266;6 at %; and M represents an element or a combination of an two or more of the elements selected from Zr, Nb, Ta, Hf, Ti, Mo, W, V, Cr, Mn, Al, Y, Ag, and rare earth elements.) (3).

The present invention relates to the synthesis of chiral epoxides via a catalytic asymmetric oxidation of olefins. Additionally, the methodology provides a method of asymmetrically oxidizing sulfides and phosphines. This asymmetric oxidation employs a catalyst system composed of a metal and a chiral bishydroxamic acid ligand, which, in the presence of a stoichiometric oxidation reagent, serves to asymmetrically oxidize a variety of substrates.

Catalytic asymmetric epoxidation

To provide a Cu-based amorphous alloy having a glass-forming ability higher than that of a Cu&#x2014;Zr&#x2014;Ti amorphous alloy and a Cu&#x2014;Hf&#x2014;Ti amorphous alloy, as well as excellent workability and excellent mechanical properties without containing large amounts of Ti. A Cu-based amorphous alloy characterized by containing 90 percent by volume or more of amorphous phase having a composition represented by Formula: Cu(Zr,Hf)(Al,Ga)[in Formula, a and b are on an atomic percent basis and satisfy 35 atomic percent&#x2266;a&#x2266;50 atomic percent and 2 atomic percent&#x2266;b&#x2266;10 atomic percent], wherein the temperature interval &#x394;Tx of supercooled liquid region is 45 K or more, the temperature interval being represented by Formula &#x394;Tx=Tx&#x2212;Tg (where Tx represents a crystallization initiation temperature and Tg represents a glass transition temperature.), a rod or a sheet having a diameter or thickness of 1 mm or more and a volume fraction of amorphous phase of 90% or more can be produced by a metal mold casting method, the compressive strength is 1,900 MPa or more, the Young's modulus is 100 GPa or more, and the Vickers hardness is 500 Hv or more.

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Miyagi, Japan

Wei Zhang