Conventional superconductivity and hysteretic Campbell penetration depth in single crystals MgCNi${}_3$

Abstract

Single crystals of MgCNi${}_3$, with areas sized up to 1 mm${}^2$, were grown by the self flux method using a cubic anvil high pressure technique. The first critical field \textit{H${}_{c1}$}, determined from a zero temperature extrapolation, is around 18 mT. Using the tunnel - diode resonator technique, the London penetration depth was measured with no applied \textit{dc} field and the Campbell penetration depth was measured with the external \textit{dc} fields up to 9T for two different sample orientations with respect to the direction of applied magnetic field. The absolute value of the London penetration depth, $\lambda (0)=245\pm 10$ nm was determined from the thermodynamic Rutgers formula. The superfluid density, ${\rho }_s=(\lambda (0)/\lambda (T){)}^2$ was found to follow the clean isotropic \textit{s}-wave behavior predicted by the weak - coupling BCS theory in the whole temperature range. The low - temperature behavior of the London penetration depth fits the BCS analytic form as well and produces close to the weak - coupling value of $\Delta (0)/k_B{T}_c=1.71$. The temperature dependence of the upper critical field, \textit{$H_{c2}$}, was found to be isotropic with a slope at \textit{T${}_c$} of -2.63 T/K and \textit{H${}_{c2}$}(0) $\approx$ 12.3 T at zero temperature. The Campbell penetration depth probes the vortex lattice response in the mixed state and is sensitive to the details of the pinning potential. For MgCNi${}_3$, an irreversible feature has been observed in the TDR response when the sample is field-cooled and warmed versus zero-field-cooled and warmed. This feature possesses a non-monotonic field dependence and has commonly been referred to as the peak effect and is most likely related to a field - dependent non - parabolic pinning potential.

References in corpus (8)

• Magnetic Penetration Depth in Unconventional Superconductors
• High magnetic field scales and critical currents in SmFeAs(O,F) crystals: promising for applications
• Th substituted SmFeAsO: structural details and superconductivity with Tc above 50 K
• Two-gap superconductivity in single crystal Lu${}_2$Fe${}_3$Si${}_5$ from penetration depth measurements
• Interplay of composition, structure, magnetism, and superconductivity in SmFeAs1-xPxO1-y
• Magnetic penetration depth in single crystals of SrPd${}_2$Ge${}_2$ superconductor
• S-wave superconductivity probed by measuring magnetic penetration depth and lower critical field of MgCNi${}_3$ single crystals
• Effect of doping on irreversible Campbell length in MgB${}_2$ single crystals

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