1966 年 21 巻 7 号 p. 1310-1323
The nuclear magnetic relaxation times in Fe3O4 have been measured. The experimental values of T1 and T2 range from 1.4 sec to 0.4 ms between 4.2° and 300°K. For the A ion, T1 and T2 are roughly equal, increasing with a magnetic field, above 120°K and show the minima at about 80° and 40°K, respectively, independent of the field. For the B ion, T1 and T2 are independent of the field with T1⁄T2≈2 from 130°K to 300°K. The results are explained semi-quantitatively by the effect of the electron migration in the B sites. Detailed calculations show: (1) T1 and T2 for the A ion are governed by the coupling of the nucleus with the migrating electrons through the dipolar interaction below 120°K and through the hyperfine and the A-B exchange interactions above 120°K; (2) the anisotropic and the isotropic hyperfine interactions give the essential contributions to T1 and T2 for the B ion, respectively.
この記事は最新の被引用情報を取得できません。