| abstract |
Tin-containing granular magentic oxide particlesncomprising spinel-type crystal represented by thenformula:n Fe 3-x Sn x O 4 nwherein x is 0.14 to 0.48, and n having a Fe 2+ content of 17 to 22% by weight, anlattice constant of 8.41 to 8.49 Å, a magnetization valuenof 20 to 50 Am 2 /kg when measured under an appliednmagnetic field of 79.6 kA/m, and a depth of a groove ofnnot more than 40 µm at which three or more continuousnlines each having a length of not less than 10 mm arendeveloped in a pigment dispersion test using a grind-meternwhen measured by Hoover's muller method accordingnto JIS K5101 (1991) 9.1. |