Strong depression of superconductivity in VN by spin fluctuations

Journal Article · Sat Nov 01 04:00:00 EST 1980 · Phys. Rev., B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.22.4284· OSTI ID:7150157

Rietschel, H; Winter, H; Reichardt, W

In this paper we argue that spin fluctuations prevent VN from being a superconductor with a transition temperature of about 30 K instead of the experimental value of 8.6 K. Thus, besides V and Nb for which similar results have been reported recently, VN provides a further and even more pronounced example for spin-fluctuation-limited high-T/sub c/ superconductivity. Our results are obtained from microscopic calculations of T/sub c/ for the refractory compounds TiN, ZrN, VN, and NbN and from magnetic susceptibility data. Among these four compounds VN is exceptional in exhibiting both a large theoretical overestimate of T/sub c/, if spin fluctuations are omitted, and a high magnetic susceptibility. Incorporating spin fluctuations within the theory of Berk and Schrieffer, the theoretical value of T/sub c/ can be brought into agreement with experiment. Calculations of the magnetic susceptibility and of T/sub c/ in nonstoichiometric VN/sub x/(0.75< or =x< or =1.0) and their comparison to experimental results of Ajami and MacCrone provide further support for our ideas.

• Research Organization: Kernforschungszentrum Karlsruhe, Institut fuer Angewandte Kernphysik I, D-7500 Karlsruhe, Postfach 3640, Federal Republic of Germany
• OSTI ID: 7150157
• Journal Information: Phys. Rev., B: Condens. Matter; (United States), Journal Name: Phys. Rev., B: Condens. Matter; (United States) Vol. 22:9; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
&amp; Refractories-- Physical Properties
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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FLUCTUATIONS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
METALS
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
ORIENTATION
PHYSICAL PROPERTIES
PNICTIDES
REFRACTORY METALS
SPIN ORIENTATION
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TITANIUM COMPOUNDS
TITANIUM NITRIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VANADIUM COMPOUNDS
VANADIUM NITRIDES
VARIATIONS
ZIRCONIUM COMPOUNDS
ZIRCONIUM NITRIDES