Fine spinel-type ferrite particles featuring high dispersibility and the process of manufacture of same
Abstract
Abstract SPINEL-TYPE SINGLE-CRYSTAL FERRITE PARTICLES ARE PROVIDED OF SUBSTANTIALLY ISOTROPIC SHAPE CONTAINING IRON AND AT LEAST ONE KIND OF DILAVENT METAL OTHER THAN IRON, THE RATIO OF THE TOTAL NUMBER OR IRON ATOMS TO THE DIVILENT METAL ATOMS BEING AT LEAST 2 TO 1, THE AVERAGE PARTICLE SIZE RANGING FROM ABOUT 0.05 TO 1.0 MICRON. THE FERRITE CRYSTALS ARE MADE BY ADMIXING AN AQUEOUS SOLUTION CONTAINING FERROUS IONS AND THE DIVALENT METAL IONS WITH 0.55 TO 3 MOL E2QUIVALENTS, RELATIVE TO ACID IN THE SOLUTION, OF AN ALKALI TO OBTAIN A SUSPENSION OF THE HYDROXIDES AT A PH OF MORE THAN 6.5 AND THEREAFTER BUBBLING AN OXIDIZING GAS INTO THE SUSPENSION MAINTAINED AT 60* C. TO 90* C. UNTIL THE HYDROXIDES DISAPPEAR AND FERRITE PARTICLES ARE FORMED.
Inventors
- 👤 T Takada
- 👤 M Kiyama
- 👤 K Iwase
Bibliographic Details
Claims Analysis
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