Chromium dioxide was introduced in the later 1960s as the first magnetic material capable of high density recording. Since that time a continuous improvement of material properties has been made possible. The most recent improvement concerns particles with coercivities well above 70 kA/m which can be prepared by a modified hydrothermal process without using expensive Ir doping. Although CrO/sub 2/ has a somewhat higher specific magnetization, the static magnetic properties of CrO/sub 2/ and cobalt-modified iron oxides are comparable. There are, however, some significant differences in recording performance. CrO/sub 2/ pigments show better print-through to noise ratios than Co-modified iron oxides of the same mean magnetic volume. There are no problems with erasability, which becomes increasingly difficult to control for high-coercivity cobalt-modified iron oxides. Finally, CrO/sub 2/ is the only pigment material which allows thermomagnetic duplication.
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机译:二氧化铬是在1960年代后期引入的,是第一种能够进行高密度记录的磁性材料。从那时起,就可以不断改善材料性能。最近的改进涉及矫顽力远高于70 kA / m的颗粒,可以通过改进的水热工艺制备这种颗粒,而无需使用昂贵的Ir掺杂。尽管CrO / sub 2 /具有较高的比磁化强度,但CrO / sub 2 /和钴改性的氧化铁的静磁性能相当。但是,记录性能存在一些显着差异。 CrO / sub 2 /颜料比相同平均磁体积的Co改性氧化铁表现出更好的透印噪声比。可擦除性没有问题,对于高矫顽力的钴改性的氧化铁,可擦除性变得越来越难以控制。最后,CrO / sub 2 /是唯一允许热磁复制的颜料材料。
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