TY - JOUR
T1 - Ferroelectric and Magnetic Properties in Room-Temperature Multiferroic GaxFe2− xO3 Epitaxial Thin Films
AU - Katayama, Tsukasa
AU - Yasui, Shintaro
AU - Hamasaki, Yosuke
AU - Shiraishi, Takahisa
AU - Akama, Akihiro
AU - Kiguchi, Takenori
AU - Itoh, Mitsuru
N1 - Funding Information:
This work was supported by a JSPS KAKENHI Grant-in-Aid for Young Scientist start-up (TK 16H06794), Young Scientist (B) (SY 15K18212), Scientific Research (A) (MI 15H02292), and the MEXT Elements Strategy Initiative to Form Core Research Center. The STEM study was supported by Tohoku University Nanotechnology Platform Project (A-15-TU-0029, A-15-TU-0039) Sponsored by MEXT, Japan.
Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/1/10
Y1 - 2018/1/10
N2 - GaFeO3-type iron oxide is a promising room-temperature multiferroic material due to its large magnetization. To expand its usability, controlling the ferroelectric and magnetic properties is crucial. In this study, high-quality GaxFe2– xO3 (x = 0–1) epitaxial films are fabricated and their properties are systematically investigated. All films exhibit room-temperature out-of-plane ferroelectricity, showing that the coercive electric field (Ec) decreases monotonically with x. Additionally, the films show in-plane ferrimagnetism with a Curie temperature (TC) >350 K at x = 0–0.6. The coercive magnetic field (Hc) decreases with x at x ≤ 0.6, but shows a constant value at x > 0.6, whereas the saturated magnetization (Ms) increases with x at x ≤ 0.6, but decreases with x at x > 0.6. X-ray magnetic circular dichroism reveals that the large magnetization at x = 0.6 is derived from Fe3+ (3d5) at octahedral sites. The controllable range of the Ec, Hc, and Ms values at room temperature (400–800 kV cm−1, 1–8 kOe, and 0.2–0.6 µB/f.u.) is very wide and differs from those of well-known multiferroic BiFeO3. Furthermore, the GaxFe2− xO3 films exhibit room-temperature magnetocapacitance effects, indicating that adjusting TC near room temperature is useful to achieve large room-temperature magnetocapacitance behavior.
AB - GaFeO3-type iron oxide is a promising room-temperature multiferroic material due to its large magnetization. To expand its usability, controlling the ferroelectric and magnetic properties is crucial. In this study, high-quality GaxFe2– xO3 (x = 0–1) epitaxial films are fabricated and their properties are systematically investigated. All films exhibit room-temperature out-of-plane ferroelectricity, showing that the coercive electric field (Ec) decreases monotonically with x. Additionally, the films show in-plane ferrimagnetism with a Curie temperature (TC) >350 K at x = 0–0.6. The coercive magnetic field (Hc) decreases with x at x ≤ 0.6, but shows a constant value at x > 0.6, whereas the saturated magnetization (Ms) increases with x at x ≤ 0.6, but decreases with x at x > 0.6. X-ray magnetic circular dichroism reveals that the large magnetization at x = 0.6 is derived from Fe3+ (3d5) at octahedral sites. The controllable range of the Ec, Hc, and Ms values at room temperature (400–800 kV cm−1, 1–8 kOe, and 0.2–0.6 µB/f.u.) is very wide and differs from those of well-known multiferroic BiFeO3. Furthermore, the GaxFe2− xO3 films exhibit room-temperature magnetocapacitance effects, indicating that adjusting TC near room temperature is useful to achieve large room-temperature magnetocapacitance behavior.
KW - ferroelectricity
KW - iron oxide
KW - magnetism
KW - multiferroics
KW - thin films
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U2 - 10.1002/adfm.201704789
DO - 10.1002/adfm.201704789
M3 - Article
AN - SCOPUS:85035138117
VL - 28
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
IS - 2
M1 - 1704789
ER -