Crystal Structure and Magnetic Properties of ϵ‐RuxFe2‐xO3 Nanosize Hard Ferrite

다국어 초록 (Multilingual Abstract)

A new series of metal‐substituted ϵ‐iron oxides, ϵ‐RuxFe2‐xO3 (x=0 (1), 0.005 (2), and 0.014 (3)) nanoparticles (average size=20 nm) is synthesized by sintering iron oxide hydroxide with ruthenium hydroxide in a silica matrix. The samples are characterized by inductively coupled plasma mass spectrometry, and energy dispersive X‐ray spectroscopy (EDS) of transmission electron microscope. The X‐ray diffraction pattern shows that ϵ‐RuxFe2−xO3 has an orthorhombic crystal structure with a space group of Pna21 and the Rietveld analyses show that Ru is doped selectively at the regular octahedral C site among the four non‐equivalent Fe sites (A, B, C, and D site). Magnetization vs. temperature plots show that the Curie temperature (TC) depends on x, and TC=498 K for 1, 497 K for 2, and 496 K for 3. Magnetization vs. external magnetic field plots indicate that the coercive field (Hc) increases from 17.7 kOe (1) to 20.3 kOe (3). This increment of 15 % on Hc is attributed to the single ion anisotropy of the magnetic spin on RuIII (4d5, S=1/2).
Magnetic mystery tour: ϵ‐Iron oxide has drawn attention as a hard ferrite due to a large coercive field. A new series of metal‐substituted ϵ‐iron oxides, ϵ‐RuxFe2‐xO3, is synthesized. The coercive field increases from 17.7 kOe (x=0) to 20.3 kOe (x=0.014). The 15 % increment of Hc was attributed to the single ion anisotropy of RuIII.