Magneto-rotation of nonmagnetic micro-crystals caused by diamagnetic anisotropy

Abstract

Preferential alignments of magnetically stable axes of diamagnetic micro-crystals dispersed in liquid ethanol were observed at a low field of 1 T for basic inorganic oxides without the use of a superconducting magnet; alignments were newly observed for corundum, forsterite, gypsum, orthoclase, KDP, and Al(OH)3. Diamagnetic anisotropy (Δχ)dia of the material was the cause of alignment. Most of the inorganic oxides, other than the above-mentioned materials, are expected to show alignment at similar field intensities. This is because their calculated (Δχ)dia values exceed 1×10−9emu∕g; it was assumed in the calculation that (Δχ)dia values originate from individual bonding orbital.