Superconductivity in quaternary niobium oxynitrides containing main group elements (M=Mg, Al, Si)

Journal Article · Sun Apr 15 04:00:00 EDT 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.01.024· OSTI ID:22012090

Ohashi, Y ^[1]; Kikkawa, S ^[1]; Felner, I; Tsindlekht, M I ^[2]; Venkateshwarlu, D; Ganesan, V ^[3]; Yakhmi, J V ^[4]

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1. Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan)
2. Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
3. UGC-DAE-Consortium for Scientific Research, Khandwa Rd, Indore (MP) 452001 (India)
4. Bhabha Atomic Research Centre, Mumbai 400085 (India)

Niobium compounds continue to be an interesting family of superconductors, with the recent addition of oxynitrides to it, which can be categorized as low-T{sub c} superconductors (LTS) because they exhibit superconductivity below T{sub c}{approx}17 K. In this paper, we report the superconducting properties of three members of the family of niobium oxynitrides, viz. (Nb{sub 0.89}Al{sub 0.11})(N{sub 0.84}O{sub 0.16}), (Nb{sub 0.95}Mg{sub 0.05})(N{sub 0.92}O{sub 0.08}) and (Nb{sub 0.87}Si{sub 0.09}{open_square}{sub 0.04})(N{sub 0.87}O{sub 0.13}). Low temperature dc and ac magnetization measurements have been performed. In addition, heat capacity has been recorded at low temperature under applied magnetic fields. A detailed analysis of the data is presented. - Graphical abstract: The doped Si oxide accompanied with some amount of cation vacancy in cubic NbN lattice induces relatively large magnetic hysteresis on isothermal hysteresis loops at 5 K of the dc magnetization up to 5 T among the four niobium oxynitrides containing main group elements, Nb{sub 1.00}(N{sub 0.98}O{sub 0.02}); (Nb{sub 0.95}Mg{sub 0.05})(N{sub 0.92}O{sub 0.08}); (Nb{sub 0.89}Al{sub 0.11})(N{sub 0.84}O{sub 0.16}), and (Nb{sub 0.87}Si{sub 0.09}{open_square}{sub 0.04})(N{sub 0.87}O{sub 0.13}). Highlights: Black-Right-Pointing-Pointer Three Nb-oxynitrides doped either with Si, Al, Mg were bulk superconductors below {approx}17 K. Black-Right-Pointing-Pointer The cation vacancies induced by doping silicon act as pinning centers. Black-Right-Pointing-Pointer The Si-doped sample had strong electron correlations.

• OSTI ID: 22012090
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. . 188; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
DOPED MATERIALS
ELECTRON CORRELATION
HYSTERESIS
MAGNETIZATION
NIOBIUM
NIOBIUM NITRIDES
OXIDES
SILICON
SPECIFIC HEAT
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TEMPERATURE RANGE 0065-0273 K