Bistability of the magnetic resonance of conduction electrons in gallium oxide

The EPR spectrum of {beta}-Ga{sub 2}O{sub 3} conduction electrons have different resonance fields in forward and backward magnetic field sweeps due to the dynamic polarization of Ga nuclei upon resonance saturation of conduction electron spins. This bistability results from a narrow line width and a strong isotropic hyperfine interaction that causes a large Overhauser shift. This phenomena is maximum at moderate electron spin system saturation. There is also evidence of a magnetic field memory. 25 refs., 9 figs.