The representative SEM images of Bi nanomaterials formed under diverse field strengths with scale bar of 5 μm: (a) 0 T, (b) 1 T, (c) 4 T, (d) 8 T. (e) The representative TEM image of the nanowire formed under 8 T, the inset is the SAED pattern of the nanowire. (f) The HRTEM image of a nanowire formed under 8 T.^[20]