Coexistence of Long-Range Magnetic Order and Superconductivity from Campbell Penetration Depth Measurements

Abstract

Application of a tunnel-diode resonator (TDR) technique for studies of the vortex response in magnetic superconductors is described. Operating at very small excitation fields and sufficiently high frequency, TDR was used to probe small-amplitude linear AC response in several types of single crystals where long-range magnetic order coexists with bulk superconductivity. Full local - moment ferromagnetism destroys superconductivity and can coexist with it only in a narrow temperature range ($\sim 0.3$ K). In contrast, weak ferromagnetic as well as antiferromagnetic orders can coexist with bulk superconductivity and may even lead to enhancements of vortex pinning. By analyzing the Campbell penetration depth we find sharp increase of the true critical current in the vicinity of the magnetic phase transitions. We conclude that critical magnetic fluctuations are responsible for this enhancement.

References in corpus (5)

• Magnetic Penetration Depth in Unconventional Superconductors
• Precise measurements of radio-frequency magnetic susceptibility in (anti)ferromagnetic materials
• Zooming into the coexisting regime of ferromagnetism and superconductivity in ErRh4B4 single crystals
• Visualization of ferromagnetic domains in TbNi${}_2$B${}_2$C and ErNi${}_2$B${}_2$C single crystals: Weak ferromagnetism and its coexistence with superconductivity
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Cited by in corpus (2)

• Campbell penetration depth in low carrier density superconductor YPtBi
• Effect of controlled artificial disorder on the magnetic properties of EuFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ ferromagnetic superconductor