Diamagnetic anisotropy of simple inorganic oxides composed of octahedral networks detected by field-induced harmonic oscillation in the high-temperature region

The detection of small diamagnetic anisotropy for five basic oxides is realized by measuring the field-induced harmonic oscillation in the temperature range from 300 K to 800 K. The Delta chi-T relationship enables the quantitative evaluation of diamagnetic anisotropy even if paramagnetic ions are present in the sample, which is generally the case for actual samples. The maximum anisotropy values between two magnetic principal axes an (1.1 +/- 0.2) x 10(-8) emu/g for muscovite, KAl2[Si3AlO10](OH)(2), (2.2 +/- 0.3) x 10(-7) emu/g for talc, Mg-3 [Si4O10](OH)(2), (2.6 +/- 0.2) x 10(-9) emu/g for brucite, Mg(OH)(2), (1.4 +/- 0.2) x 10(-9) emu/g for gibbsite, Al(OH)(3), and (4.2 +/- 0.3) x 10(-9) emu/g for diaspore, AlOOH.