High-Throughput Screening of Ultraviolet--Visible Magnetooptical Properties of Spinel Ferrite (Zn,Co)Fe2O4 Solid Solution Epitaxial Film by a Composition-Spread Approach

Spinel ferrite Zn 1-x Co x Fe 2 O 4 ($0\leq x\leq 1$) (111) composition-spread thin film was epitaxially grown on an MgAl 2 O 4 (111) substrate by combinatorial pulsed laser deposition. Sequential deposition of the two end-compounds with monolayer-period led to the formation of solid solution with a...

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Published inApplied physics express Vol. 3; no. 10; pp. 103001 - 103001-3
Main Authors Iwasaki, Yosuke, Fukumura, Tomoteru, Kimura, Hisamichi, Ohkubo, Akira, Hasegawa, Tetsuya, Hirose, Yasushi, Makino, Takayuki, Ueno, Kazunori, Kawasaki, Masashi
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.10.2010
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Summary:Spinel ferrite Zn 1-x Co x Fe 2 O 4 ($0\leq x\leq 1$) (111) composition-spread thin film was epitaxially grown on an MgAl 2 O 4 (111) substrate by combinatorial pulsed laser deposition. Sequential deposition of the two end-compounds with monolayer-period led to the formation of solid solution with addressable composition. Point-by-point ultraviolet--visible magnetic circular dichroism and Faraday rotation angle spectra showed a significant variation with $x$, and the latter spectra combined with absorption spectra led to the rapid evaluation of magnetooptical performance factor as functions of $x$ and photon energy. A significant enhancement of ultraviolet magnetooptical effect was observed by substituting a small amount of Zn (${\leq}30$ at. %) for Co in CoFe 2 O 4 .
Bibliography:(a) A unit cell of spinel AB 2 O 4 structure. Red tetrahedron and blue octahedron denote AO 4 and BO 6 polyhedra, respectively, where green circles denote oxygen sites. A cubic diagonal length of the unit cell along $\langle 111\rangle$ corresponds to 1.46 nm. (b) Growth sequence of (Zn 1-x Co x ) Fe 2 O 4 composition-spread thin film. Wedge-shaped ZnFe 2 O 4 and Co Fe 2 O 4 layers with a unit cell thick at maximum are alternatively deposited to reach a total film thickness of 70 nm. (a) Schematic illustration of (Zn 1-x Co x )Fe 2 O 4 composition-spread thin film, where the color denotes composition. (b) Evaluated $x$ in Zn 1-x Co x Fe 2 O 4 and (c) out-of-plane lattice parameter $d_{222}$ at each position. $d_{222}$ values of ZnFe 2 O 4 and CoFe 2 O 4 bulk specimens are also plotted. Magnetic field dependence of magnetic circular dichroism (MCD) of Zn 1-x Co x Fe 2 O 4 with different $x$ at room temperature. Photon energy is 2.25 eV. (a) Magnetic circular dichroism (MCD) at 2 T, (b) Faraday rotation angle ($\theta_{\text{F}}$) at 2 T, (c) absorption coefficient ($\alpha$), and (d) perfor mance factor as a function of photon energy for Zn 1-x Co x Fe 2 O 4 with different $x$ at room temperature. Line colors correspond to values of $x$ displayed in (c). Reported values of the performance factors of poly crystalline CoFe 2 O 4 and (Zn 0.31 Co 0.69 )Fe 2 O 4 films (ref. ) are shown respectively by open circles and squares in (d).
ISSN:1882-0778
1882-0786
DOI:10.1143/APEX.3.103001