PERMANENT MAGNET AND METHOD FOR PREPARATION THEREOF

• Main Authors: ODA, ETSUSHI, TOYOTA, SACHIO, HOSOKAWA, SEIICHI
• Format: Patent
• Language: English; French; Japanese
• Published: 15.08.2002
• Edition: 7
• Subjects: ARTIFICIAL STONE; BASIC ELECTRIC ELEMENTS; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; CONCRETE; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OFSOLID INORGANIC COMPOUNDS; INDUCTANCES; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; INORGANIC CHEMISTRY; LIME, MAGNESIA; MAGNETS; METALLURGY; PHYSICS; REFRACTORIES; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; SLAG; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSFORMERS; TREATMENT OF NATURAL STONE

A method for preparing a ferrite magnet, wherein a ferrite having a hexagonal W type magneto-plumbite structure is added to a ferrite which has a hexagonal M type magneto-plumbite structure and in which a part of Sr, Ba, Pb or Ca has been substituted with La and optionally at least one element selected from among rare earth elements including Y and Bi during pulverization to a fine powder; and a ferrite magnet prepared by using the method. The above method which comprises the addition of a ferrite having a hexagonal W type magneto-plumbite structure to a ferrite having a hexagonal M type magneto-plumbite structure during the pulverization allows the preparation of a ferrite magnet having improved magnetic characteristics with the addition of a reduced amount of an element such as Co, Ni, Mn or Zn. Procédé de production d'un aimant en ferrite selon lequel une ferrite ayant une structure hexagonale de magnétoplombite de type W est ajoutée à une ferrite ayant une structure hexagonale de magnétoplombite de type M pendant la pulvérisation en poudre fine. Dans ledit aimant, une partie de Sr, Ba, Pb ou Ca a été substituée par La et éventuellement au moins un élément choisi parmi les terres rares, dont Y et Bi. La présente invention concerne également un aimant de ferrite préparé selon ledit procédé. Ledit procédé qui consiste à ajouter une ferrite ayant une structure hexagonale de magnétoplombite de type W à une ferrite ayant une structure hexagonale de magnétoplombite de type M pendant la pulvérisation permet la préparation d'un aimant en ferrite à caractéristiques magnétiques améliorées, avec ajout d'une quantité réduite d'un élément tel que Co, Ni, Mn ou Zn.