论文标题
使用MUSR测量研究的中级超导体CEIR3的配对对称性
Pairing symmetry of an intermediate valence superconductor CeIr3 investigated using muSR measurements
论文作者
论文摘要
我们通过使用磁化，热容量和MUON自旋旋转和放松（$ $ $ $ SR）测量，研究了菱形中间价超导体CEIR $ _3 $的散装和显微特性。磁敏感性表明$ t_ \ mathrm {c} = 3.1 $ 〜k以下的大量超导性。热容量数据还揭示了$ t_ \ mathrm {c} = 3.1 $ 〜k的散装超导过渡，第二个弱异常接近1.6〜k。在$ t _ {\ mathrm {c}} $中，加热容量的跳跃$ΔC$/$umγt_ {\ mathrm {c}} \ sim 1.39（1）$，略低于BCS弱耦合限量为1.43。横向场$ $ $ SR的测量表明，具有2 $δ（0）/k _ {\ MathRM {\ Mathrm {b}} t _ {\ Mathrm {c}}} = 3.76（3）$，非常接近3.56，bcc gap forbc gap forbc gap valybl Valival forbc gap forbc gap valive forbc gap valive forbc gap valive forbc gap gap valive forbc gap gap forebl bc gap forebl bcc gap for。根据磁穿透深度的温度变化，我们还确定了伦敦的穿透深度$λ_ {\ Mathrm {l}}（0）= 435（2）$ 〜nm，载体的有效质量增强$ M^{*} = 1.69（*1.69（1）M _ {1） $ n _ {\ mathrm {s}} = 2.5（1）\ times 10^{26} $ carriers m $^{ - 3} $。 The fact that LaIr$_3$, with no $4f$-electrons, and CeIr$_3$ with $4f^{n}$ electrons where $n \le 1$-electron (Ce ion in a valence fluctuating state), both exhibit the same $s$-wave gap symmetry indicates that the physics of these two compounds is governed by the Ir-$d$ band near the Fermi-level,这与先前的频带结构计算一致。
We have investigated the bulk and microscopic properties of the rhombohedral intermediate valence superconductor CeIr$_3$ by employing magnetization, heat capacity, and muon spin rotation and relaxation ($μ$SR) measurements. The magnetic susceptibility indicates bulk superconductivity below $T_\mathrm{C} = 3.1$~K. Heat capacity data also reveal a bulk superconducting transition at $T_\mathrm{C} = 3.1$~K with a second weak anomaly near 1.6~K. At $T_{\mathrm{C}}$, the jump in heat capacity $ΔC$/$γT_{\mathrm{C}} \sim 1.39(1)$, is slightly less than the BCS weak coupling limit of 1.43. Transverse-field $μ$SR measurements suggest a fully gapped, isotropic, $s$-wave superconductivity with 2$Δ(0)/k_{\mathrm{B}}T_{\mathrm{C}} = 3.76(3)$, very close to 3.56, the BCS gap value for weak-coupling superconductors. From the temperature variation of magnetic penetration depth, we have also determined the London penetration depth $λ_{\mathrm{L}}(0) = 435(2)$~nm, the carriers' effective mass enhancement $m^{*} = 1.69(1)m_{\mathrm{e}}$ and the superconducting carrier density $n_{\mathrm{s}} = 2.5(1)\times 10^{26}$ carriers m$^{-3}$. The fact that LaIr$_3$, with no $4f$-electrons, and CeIr$_3$ with $4f^{n}$ electrons where $n \le 1$-electron (Ce ion in a valence fluctuating state), both exhibit the same $s$-wave gap symmetry indicates that the physics of these two compounds is governed by the Ir-$d$ band near the Fermi-level, which is in agreement with previous band structure calculations.
