Preparation and properties of a new ternary phase Mg{sub 3+x}Ni{sub 7−x}B{sub 2} (0.17≤x≤0.66) and its Cu-doping effect

Journal Article · Sun Mar 15 00:00:00 EDT 2015 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2015.01.018· OSTI ID:22475632

Liao, Chang-Zhong ^[1]; Dong, Cheng ^[1]; Shih, Kaimin ^[2]; Zeng, Lingmin ^[3]; He, Bing ^[1]; Cao, Wenhuan ^[1]; Yang, Lihong ^[1]

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1. Institute of Physics, Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, Beijing 100190 (China)
2. Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR (Hong Kong)
3. Key Laboratory of Nonferrous Metals and New Processing Technology of Materials, Ministry of Education, Guangxi University, Nanning, Guangxi 530004 (China)

In recent years, the materials in the B–Mg–Ni system have been intensively studied due to their excellent properties of hydrogen storage and superconductivity. Solving the crystal structure of phases in this system will facilitate an understanding of the mechanism of their physical properties. In this study, we report the preparation, crystal structure and physical properties of a new ternary phase Mg{sub 3+x}Ni{sub 7−x}B{sub 2} in the B–Mg–Ni system. The Mg{sub 3+x}Ni{sub 7−x}B{sub 2} phase was prepared by solid-state reactions at 1073 K and its crystal structure was determined and refined using X-ray powder diffraction data. The Mg{sub 3+x}Ni{sub 7−x}B{sub 2} phase crystallizes in the Ca{sub 3}Ni{sub 7}B{sub 2} structure type (space group R-3m, no. 166) with a=4.9496(3)–5.0105(6) Å, c=20.480(1)–20.581(1) Å depending on the x value, where x varies from 0.17 to 0.66. Two samples with nominal compositions Mg{sub 10}Ni{sub 20}B{sub 6} and Mg{sub 12}Ni{sub 18}B{sub 6} were characterized by magnetization and electric resistivity measurements in the temperature range from 5 K to room temperature. Both samples exhibited metallic behavior and showed spin-glass-like behavior with a spin freezing temperature (T{sub f}) around 33 K. A study of the Cu-doping effect showed that limited Cu content can be doped into the Mg{sub 3+x}Ni{sub 7−x}B{sub 2} compound and T{sub f} decreases as the Cu content increases. - Graphical abstract: The crystal structure of the Mg{sub 3+x}Ni{sub 7−x}B{sub 2} phase. - Highlights: • The crystal structure and solid solution range of Mg{sub 3+x}Ni{sub 7−x}B{sub 2} were revealed. • The magnetization and electrical resistivity of Mg{sub 3+x}Ni{sub 7−x}B{sub 2} were studied. • The Cu-doping effect of Mg{sub 3+x}Ni{sub 7−x}B{sub 2} was investigated.

• OSTI ID: 22475632
• Journal Information: Journal of Solid State Chemistry, Vol. 226; Other Information: Copyright (c) 2015 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

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
BORON ALLOYS
CONCENTRATION RATIO
CRYSTAL STRUCTURE
DOPED MATERIALS
FREEZING
HYDROGEN STORAGE
MAGNESIUM ALLOYS
MAGNETIZATION
NICKEL BASE ALLOYS
SOLID SOLUTIONS
SOLIDS
SPIN GLASS STATE
SUPERCONDUCTIVITY
TEMPERATURE RANGE 0273-0400 K
TERNARY ALLOY SYSTEMS
X-RAY DIFFRACTION