MN-ZN FERRITE SINGLE CRYSTAL AND ITS PRODUCTION

• Main Authors: NAKAMURA EIJI, IWANO EIICHIRO, KAMISAKA EIJI, YONEDA SUKEHITO, SHIBATA SAKAE
• Format: Patent
• Language: English
• Published: 27.05.1992
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PURPOSE:To obtain the subject single crystal having a uniform composition, free from remarkable contamination of platinum and excellent in crystallinity at a low cost by thoroughly fusing the raw material and subsequently allowing the fused raw material to stand for one hour or longer in growing the single crystal. using a crucible made of Pt or Pt-Rh alloy. CONSTITUTION:A crucible 1 made of Pt or Pt-Rh alloy is set to a supporting unit 7 linked to an elevating unit 10 and placed in an electric furnace 5. A prescribed amount of raw material powder is then charged to the crucible 1, heated to form a fused liquid 4 and allowed to stand in that state for one hour or longer. The crucible 1 is then slowly lowered so that an Mn-Zn ferrite single crystal may be produced from the bottom of the crucible 1 taking a long time. A sintered ZnO rod 2 is suspended from a sintered rod-elevating unit 3 arranged over the electric furnace 5 to a position right above the surface of the fused liquid 4 and ZnO is sublimed to prevent evaporation of ZnO from the fused liquid 4. Composition variation of the single crystal can be prevented thereby, thus obtaining the objective Mn-Zn ferrite single crystal having <=500ppm contamination of Pt and/or Rh.