Attempt to detect diamagnetic anisotropy of oxides with isotropic crystal structure by measuring its rotational oscillation in strong magnetic field

Sensitivity to detect diamagnetic anisotropy Δχ_DIA of inorganic oxides was improved by increasing intensity of horizontal field from 1.6 T to 5.0 Tesla. The field induced a rotational oscillation of a magnetically stable axis of a sample, which was suspended with a thin fiber. Accurate Δχ values are obtained when restoration torque of the fiber is negligibly small compared to torque due to magnetic anisotropy. Accordingly, Δχ value at a level of 5×10^-10 emu/g can be acquired, even if the mass of the sample is relatively small (0.318 g). Necessity of realizing Δχ measurement at low temperature is discussed, which realizes separation of Δχ _DIA from a paramagnetic anisotropy caused by isolated magnetic ions.