In this paper, the superconducting properties of ${\text{YSn}}_3$ are reported. ${\text{YSn}}_3$ has a cubic ${\text{AuCu}}_3$-type structure with the space group $Pm\overline{3}m$. Magnetic susceptibility, electrical resistivity, and specific-heat data showed that ${\text{YSn}}_3$ is a superconductor with a superconducting transition temperature $\left(T_{\text{c}}\right)$ of 7 K. The magnetization versus magnetic field $\left(M\text{−}H\right)$ curve shows the typical type-II superconducting behavior. The estimated lower critical field $H_{\text{c}1}\left(0\right)$ and the upper critical field $H_{\text{c}2}\left(0\right)$ are about 90 Oe and 3000 Oe, respectively. The penetration depth $\lambda \left(0\right)$ and coherence length $\xi \left(0\right)$ are calculated to be approximately 270 nm and 66 nm, respectively, using the Ginzburg-Landau equations. The estimated Sommerfeld coefficient ${\gamma }_{\text{N}}$ is $7.57\text{mJ}/\text{mol}{\text{K}}^2$. The normalized specific heat jump $\Delta C/{\gamma }_{\text{N}}{T}_{\text{c}}$ is estimated to be about 2.19, which is higher than the value predicted by the BCS theory in the weak-coupling limit, i.e., $\Delta C/{\gamma }_{\text{N}}{T}_{\text{c}}=1.43$. This fact indicates that superconductivity in ${\text{YSn}}_3$ exists in the strong-coupling regime. The difference between $T_{\text{c}}$ of $\text{Ln}{X}_3$ ($X=\text{family}$ of 13 or 14 elements) compounds is discussed to compare their physical properties.

• Received 23 February 2010

DOI:https://doi.org/10.1103/PhysRevB.82.094517