Anisotropy of electric resistance and upper critical field in magnetic superconductor Dy${}_{0.6}$Y${}_{0.4}$Rh${}_{3.85}$Ru${}_{0.15}$B${}_4$

Abstract

We have measured temperature dependencies of the electric resistance $R$ and upper critical magnetic field $H_{c2}$ of a magnetic superconductor Dy${}_{0.6}$Y${}_{0.4}$Rh${}_{3.85}$Ru${}_{0.15}$B${}_4$. The measurements were made for different angles $\phi$ of magnetic field inclination to the direction of measuring current and revealed strong anisotropy of the behavior of $R(T)$ and the values of $H_{c2}(T)$. By using the Werthamer-Gelfand-Hohenberg theory, we determined the Maki parameter $\alpha$ and the parameter of the spin-orbital interaction. For $\phi =0^{\circ }$ and $90^{\circ }$ both parameters are close to zero, thus the magnitude of $H_{c2}(0)\approx 38$ kOe is basically limited by the orbital effect. At $\phi =45^{\circ }$, a large value of the parameter $\alpha =4.2$ indicates dominating role of the spin-paramagnetic effect in the suppression of $H_{c2}(0)$ down to $8.8$ kOe. We suggest that such behavior of $R(T)$ and $H_{c2}(T)$ is caused by internal magnetism of the Dy atoms which may strongly depend on the magnetic field orientation.

4 pages, 3 figures, submitted to Physica C

Cited by in corpus (1)

• Anomalous behaviour of the temperature dependencies of the upper critical fields in (Dy1-xErx)Rh3.8Ru0.2B4 (x=0, 0.2, 0.4)