Figure 3: Millimetre wave absorption and millimetre wave magnetic rotation of ε-RhxFe2−xO3 nanomagnets.
From: Hard magnetic ferrite with a gigantic coercivity and high frequency millimetre wave rotation
(a) Millimetre wave absorption spectra of ε-RhxFe2−xO3 under a zero-magnetic field at room temperature for x=0 (blue), x=0.04 (light blue), x=0.07 (green), x=0.11 (orange) and x=0.14 (red) measured by THz-TDS. Inset plots the resonance frequency (fr) versus coercive field (Hc). Colours of the dots are consistent with the x values of the absorption spectra. Black line is to guide the eye. (b) Millimetre wave magnetic rotation and ellipticity change of ε-Rh0.14Fe1.86O3. Rotation angle (red dotted line) and ellipticity (black dotted line) spectra measured by irradiating from the N-pole side (left) and S-pole side (right) of the sample using THz-TDS. Solid lines are to guide the eye. (c) Schematic illustration of the magnetic rotation and ellipticity change of the propagated millimetre wave due to the optically induced magnetic dipole transition. The green and ochre arrows indicate the magnetic field and electric field components of the impulsive terahertz wave pulse, respectively. Red and blue sides of the disc denote the N- and S-poles of the magnetized pellet sample.
