High-frequency millimeter wave absorption of indium-substituted ε-Fe2O3 spherical nanoparticles (invited)

摘要: In this work, we prepared indium-substituted e-iron oxide (e-InxFe2−xO3) spherical nanoparticles by a combination method of reverse-micelle and sol-gel techniques. The powder X-ray diffraction pattern with Rietveld analysis shows that e-InxFe2−xO3 has an orthorhombic crystal structure (space group: Pna21), the In3+ ions mainly replace Fe3+ at B site among four nonequivalent sites (A–D sites). magnetic measurements show coercive field (Hc) 300 K decreases increasing x, i.e., Hc = 21.9 kOe (x = 0), 12.2 kOe (x = 0.04), 11.6 kOe (x = 0.09), 7.8 kOe (x = 0.13), 5.9 kOe (x = 0.18). Millimeter wave absorption was measured terahertz time-domain spectroscopy, decrease resonance frequency (fr) is observed, fr = 182 GHz 160 GHz 143 GHz 123 GHz 110 GHz This in fr value understood anisotropy, which caused replacement (S = 5/2) wit...