High-pressure synthesis, crystal structure and magnetic property of ilmenite-type FeGeO{sub 3}

Journal Article · Fri Feb 15 00:00:00 EST 2013 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.11.020· OSTI ID:22150060

Nakatsuka, Daisuke ^[1]; Yoshino, Takashi ^[2]; Kano, Jun; Hashimoto, Hideki; Nakanishi, Makoto; Takada, Jun; Fujii, Tatsuo ^[1]

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1. Graduate School of Natural Science and Technology, Okayama University, Tsushiuma-naka 3-1-1, Okayama 700-8530 (Japan)
2. Institute for Study of the Earth's Interior, Okayama University, Misasa, Tottori 682-0193 (Japan)

We synthesized well-crystallized ilmenite-type FeGeO{sub 3} to investigate its structural and magnetic properties. Ilmenite-type FeGeO{sub 3} were synthesized by high-pressure synthesis technique using a Kawai-type multi-anvil apparatus. Their structural and magnetic properties were examined by XRD analysis with Rietveld refinement, transmission electron microscopy, Moessbauer spectroscopy and SQUID-magnetization measurements. The subsequent annealing after the high-pressure synthesis was effective to improve the crystallinity of the ilmenite-type FeGeO{sub 3}. The primary particle size of ilmenite-type FeGeO{sub 3} was {approx}15 nm. Some particles seemed to be covered with non- or poorly crystalline phase even after the annealing, and others showed a lamellar microstructure parallel to the (0 0 1) plane. Theilmenite-type FeGeO{sub 3} showed typical antiferromagnetic behavior with the Neel temperature of 79 K. - Graphical abstract: Crystal structure, transmission electron micrograph and temperature dependent susceptibility of ilmenite-type FeGeO{sub 3}. Highlights: Black-Right-Pointing-Pointer Ilmenite-type FeGeO{sub 3}, a novel polymorphism of FeGeO{sub 3} was successfully synthesized. Black-Right-Pointing-Pointer It was synthesized by using high pressure technique at 23.5 GPa at 500 Degree-Sign C. Black-Right-Pointing-Pointer Subsequent annealing in vacuum was effective to improve the crystallinity. Black-Right-Pointing-Pointer Its primary particle size was {approx}15 nm, and some grains had lamellar microstructure. Black-Right-Pointing-Pointer It showed typical antiferromagnetic behavior with the Neel temperature of 79 K.

• OSTI ID: 22150060
• Journal Information: Journal of Solid State Chemistry, Vol. 198; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANNEALING
ANTIFERROMAGNETISM
CRYSTAL STRUCTURE
ILMENITE
MAGNETIC PROPERTIES
MAGNETIZATION
MICROSTRUCTURE
MOESSBAUER EFFECT
NEEL TEMPERATURE
PARTICLE SIZE
PRESSURE RANGE MEGA PA 10-100
SQUID DEVICES
SYNTHESIS
TEMPERATURE DEPENDENCE
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION