| 摘要 |
PURPOSE:To provide a powdery magnetic material of high saturation and low Curie point by using an oxide composition that has a crystal structure of hexagonal ferrite. CONSTITUTION:A powdery material for magnetic recording contains 14-20 atomic percent strontium oxide and/or barium oxide, 20-40 atomic percent chromium oxide, 2-15 atomic percent zinc oxide and/or magnesium oxide, 2-15 atomic percent tin oxide, and the remainder of iron oxide and irreversible impurity. This material has a crystal structure of hexagonal ferrite, and it has high saturation (sigmas) greater than 15emu/g under the conditions of Curie point below 155 deg.C and coercive force of 5 kOe. |
