论文标题
CEPTSI2中磁基态的压力依赖性
Pressure dependence of the magnetic ground state in CePtSi2
论文作者
论文摘要
据报道，CEPTSI2在环境压力下显示出低于T*= 1.8 K的抗磁磁序，〜1.2 GPa的价状态变化，超导性在1.4和2.1 GPa之间，最大过渡温度为0.14 k [T。 Nakano等人，物理。 Rev. B 79，172507（2009）]。我们已经进行了多晶和单晶中子衍射实验，以确定环境和高压下的磁结构。我们发现，在t_ {sdw} 〜1.25 K以下的环境压力下，与（0.32，0，0.11）的磁性传播载体的不均匀磁峰具有（0.32，0，0.11）。那些来自旋转密度波的磁性峰，沿着旋转密度波和易于轴沿C轴的易于轴和平均阶段的均值（5）MU_B的平均值（5）MU_B的平均值， t_ {sdw}。施加压力，磁性传播载体显示没有变化，磁顺序在1.0 GPA左右消失，这比超导阶段的临界压力低得多。结果表明，除了磁波动外，可能在超导配对机制中起主要作用。
CePtSi2 was reported to exhibit an antiferromagnetic order below T*=1.8 K at ambient pressure, a valence state change at ~1.2 GPa, and superconductivity in the range between 1.4 and 2.1 GPa with the maximum transition temperature of 0.14 K [T. Nakano et al., Phys. Rev. B 79, 172507 (2009)]. We have performed polycrystalline and single crystal neutron diffraction experiments to determine the magnetic structure under ambient and high pressures. We found that incommensurate magnetic peaks with the magnetic propagation vector of (0.32, 0, 0.11) at ambient pressure below T_{SDW}~1.25 K. Those magnetic peaks which originate from a spin-density-wave order with the easy axis along the c axis and an averaged ordered moment of 0.45(5) mu_B, suggesting that there may be an intermediate phase between T* and T_{SDW}. Applying pressures, the magnetic propagation vector shows no change and the magnetic order disappears around 1.0 GPa, which is much lower than the critical pressure for the superconducting phase. The results suggest that other than magnetic fluctuations may play a primary role in the superconducting pairing mechanism.
