Авторы: Day R., Fuller M.

1977 г.

Phys.Earth Planet.Int.

     Sized fractions of x = 0.6, 0.4, 0.2 and 0.0 titanomagnetites were studied with a vibration magnetometer. In thecoarse particles (d > 150 pm), no compositional dependence of hysteresis parameters was found. Hc was less than 50 Oe, HPJHC > 4 and JR/Is < 1 ~2, reflecting multi-domain behaviour. In contrast, fine particles (d 0.1 pm) revealed systematic grain-size dependence of parameters with coercive force as high as 2,000 Oe in x = 0.6 titanomagnetite. Grain-size dependence studies revealed broad transition sizes for the onset of true multi-domain behaviour depending upon which factor is chosen. In magnetite it varies from 10 to 20 pm. The experimental critical size for single-domain behaviour for magnetite is about 0.1 pm and forx = 0.6 titanomagnetite 1—2 pm.

Файл: 114.pdf