U.S. Philips Corporation

Other

Kurt H Buschow

Dirk B De Mooij

Johann R Van Beek

Jan Mulder

Johannes J Willems

Arjan Noordermeer

Andries R Miedema

Harmannus Hinderikus Van Mal

Pieter G Van Engen

Reinoud Van Mens

Roelof M Van Essen

Ronald Jongebreur

Theodora H Jacobs

Petrus P Van Engelen

Franciscus H Feijen

Dirk B De Mooy

Hendrik A Van Esveld

Johannes S Van Wieringen

A description is given of a method of manufacturing a permanent magnet on the basis of NdFeB. In this method a powder of NdFeB and a powder of a Ga alloy, consisting mainly of Ga and one or more than one rare earth metals (RE), is mixed to form a mixture which is subsequently aligned, compressed and sintered. Such alloys can be ground into homogeneous, fine-grain powders in a simple manner. The composition of the alloy preferably corresponds to the formula REGa.sub.x, where x=1 or x=2. Alloys which are very suitable contain Dy and/or Tb as the rare earth metal.

Method of manufacturing a permanent magnet on the basis of NdFeB

A description is given of a hard magnetic material whose composition corresponds to the formula RE.sub.2 Fe.sub.17 C.sub.x, RE consisting of at least 70 at. % of Sm. This material has a relatively large uniaxial magnetic anisotropy and a relatively high T.sub.c and is very suitable for use in permanent magnets.

Hard magnetic material and magnet manufactured from such hard magnetic

The invention relates to new hard magnetic materials which have an intermetallic compound of tetragonal crystal structure of the ThMn.sub.12 type. The intermetallic compound has the gross formula ZA(Me.sup.I.sub.1-x Me.sup.II.sub.x).sub.12, wherein ZA is a rare earth metal from the group Sm, Er, Tm. Me.sup.I is Fe, Co or a mixture of the two, Me.sup.II is Ti, V, Cr or Si and x=0.1-0.2, preferably 0.12-0.17.

Hard magnetic material

A magnetic material of the composition Fe.sub.79-x-y B.sub.21+x R.sub.y in which R is a rare earth element or a mixture of such elements and wherein -5&lt;x&lt;5 and &lt;y.ltoreq.+4.8 The preferred rare earth element is neodymium and/or praseodymium.

Magnetic material comprising iron, boron and a rare earth metal

A permanent magnetic material having a main phase of the R.sub.2 (Co.sub.1-x Fe.sub.x).sub.14 B type in which R represents Nd, Pr and/or Tb, or a combination of one of these with at least one other member of the group of rare earth metals and Y, and in which O.ltoreq.x.ltoreq.0.2. Magnets can be produced of this material by means of a powder-metallurgic process resulting in magnets having a combination of a high T.sub.c and a high .sub.I H.sub.c.

Magnetic material comprising an intermetallic compound of the rare earth

A method of producing thin magnetic layers is described. The material composition is defined by the formula REFe.sub.12-x T.sub.x, wherein RE is an element chosen from the set formed by Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Lu and Y, wherein T is an element chosen from the set formed by Si, Ti, V, Cr, Mo and W, and wherein 1.ltoreq.x.ltoreq.4. This material is applied by means of a deposition technique from the vapor phase.

Method of producing the magnetic metallic layers having a low thermal

A magnetooptical recording element has a substrate bearing a magnetooptical recording layer. The recording layer is crystalline and comprises a compound of the formula R.sub.2 T.sub.14 B, wherein R is a rare earth metal or a combination of two or more rare earth metals, and T is a transition metal or a combination of two or more transition metals, in particular Fe or Co or a mixture thereof. A magnetooptical recording device comprises such a magnetooptical recording element.

Magnetooptical recording element and a magnetooptical recording device

A magneto-optical device for varying the state of polarization of a reflected or transmitted light beam having a wavelength which lies in particular in the range between 0.6 and 0.9 microns. The device has a magneto-optically active layer formed from a platinum-manganese-antimony alloy, at least 80 atomic percent of which has the composition Pt.sub.1 Mn.sub.1 Sb.sub.1 and has a C1.sub.b crystal structure.

Magneto-optical device

An Invar type alloy on the basis of iron is formed by an intermetallic compound having a cubic crystal structure of the NaZn.sub.13 type having a nominal composition La(FeCoX).sub.13, wherein X is Si or Al. By subjecting the present intermetallic compound after melting to a tempering treatment at 800.degree.-1,000.degree. C. and cooling it in an accelerated manner, a brittle material is obtained which can be ground to form a powder. From this powder, articles having any desired (optionally complicated) shape can be produced by means of powder metallurgy. By mixing powders of two different intermetallic compounds, a material can be obtained having a substantially negligible coefficient of linear thermal expansion in the temperature range from 0.degree. C. to 200.degree. C.

Invar alloy on the basis of iron having a crystal structure of the cubic

An invar alloy on the basis of iron is formed by an intermetallic compound having a cubic crystal structure of the NaZn.sub.13 type having nominal composition La(FeCoX).sub.13, wherein X is Si or Al. By subjecting the present intermetallic compound after melting to a tempering treatment at 800.degree.-1,000.degree. C. and cooling it in an accelerated manner, a brittle material is obtained which can be ground to form a powder. From this powder, articles having any desired (optionally complicated) shape can be produced by means of powder metallurgy. By mixing powders of two different intermetallic compounds, a material can be obtained having a substantially negligible coefficient of linear thermal expansion in the temperature range from 0.degree. C. to 200.degree. C.

Alloys consisting of from 64 to 77 atomic percent of manganese with the remainder zirconium are not suitable without further processing as a material for storing hydrogen at technically desired pressures. This property can be advantageously influenced by a heat treatment until a homogeneous C14 type of Laves phase has been obtained.

Method of preparing a hydrogen-absorbing alloy

An electrochemical cell having a negative electrode comprising a compound derived from LaNi.sub.5, in which La is optionally substituted by a plateau pressure-increasing element and in which Ni is substituted entirely or partly by a plateau pressure-reducing element, for example, Co and/or Cu, with the object of considerably reducing volume steps and hence crack formation of the intermetallic compound during charging and discharging. Moreover, the corrosion of the intermetallic compound is counteracted by adding small quantities of Al, Cr and/or Si, which metals enhance the formation of a protecting oxide layer.

Electrochemical cell comprising stable hydride-forming material

A material for storing hydrogen consisting of a titanium-iron alloy having 5-30 at.% of one or more metals of the group chromium, zirconium, manganese and vanadium.

Method of preparing titanium iron-containing material for hydrogen

A filling mass for low-temperature regenerators comprising one or more of the compounds of the formula A.sub.1-x B.sub.x Rh.sub.1-y X.sub.y, wherein A = Sm, Gd, Tb, Dy or a mixture thereof, wherein B = Ho, Er, Tm, Yb or a mixture thereof, wherein X = Cu, Zn, Ru, Pd, Ag, Re, Os, Ir, Pt, Au or a mixture thereof, and wherein 0.ltoreq..times..ltoreq.1 and 0.ltoreq.y&lt;0.2.

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Eindhoven, Netherlands

Kurt H Buschow