Hydrothermal synthesis of chromium dioxide powders and their characterisation
Chromium dioxide (CrO2) powders have been synthesised by decomposing CrO3 and Cr2O5 powders under hydrothermal conditions in the temperature range of 300–500°C and pressure range of 250–1200 bars. Oxides of antimony and iron have been used as modifiers to induce acicular morphology. A novel method of using alkali metal salts such as chlorides and carbonates as mineralisers produces CrO2 with superior magnetic characteristics. The particle size distributions have been correlated with the magnetic properties of the materials. The products obtained have properties rendering them useful for magnetic recording applications.
KeywordsHydrothermal synthesis chromium dioxide magnetic recording material particle size distribution
Unable to display preview. Download preview PDF.
- Arthur P 1960 U.S. Pat2 956 955Google Scholar
- Arthur P and Ingram J N 1974 U.S. Pat 3,117,093Google Scholar
- Basile G and Mazza A 1977Ger. Offen. 2,648,305Google Scholar
- Claude R, Lorthioir G and Mazieres C 1968Comptes Rendus C266 462Google Scholar
- Ingram J N 1960 U.S. Pat3 923 684Google Scholar
- Ingram J N and Swoboda T J 1962 U.S. Pat 3,034,988Google Scholar
- Jaleel V A, Aswath C and Kannan T S 1980Mag. Soc. Trans. India 4 18Google Scholar
- Jaleel V A, Aswath C, Sivaraman M, Bhaskaran T A and Kannan T S 1981 Presented at 13th Annual meeting of the Electron Microscopic Soc. India and fifty years of electron microscopy symposium, I.I.Sc., BangaloreGoogle Scholar
- Montiglio U, Aspes P, Basse G and Gallinotti E 1976 U.S. Pat3, 979, 310Google Scholar
- Ranjan M and Karunakar K 1979 Paper presented at the III Annual technical meeting of Magnetic Society of India at Jadavpur, Calcutta.Google Scholar
- Robinson J W and Hockings E F 1972RCA Rev. 33 399Google Scholar
- Swoboda 1960 U.S. Pat.3 923 685Google Scholar