Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan.
Phys Rev Lett. 2012 Jan 27;108(4):047201. doi: 10.1103/PhysRevLett.108.047201. Epub 2012 Jan 24.
We show that bulk gold (Au) exhibits temperature-independent paramagnetism in an external magnetic field by x-ray magnetic circular dichroism spectroscopy at the Au L(2) and L(3) edges. Using the sum-rule analysis, we obtained a magnetic moment of 1.3 × 10(-4) μB/atom in an external magnetic field of 10 T and a paramagnetic susceptibility of 8.9 × 10(-6) for the 5d orbit. The induced paramagnetism in bulk Au is characterized by a large (≈ 30%) orbital contribution. This orbital component was retained even when Au atoms formed nanoparticles, playing an important role in stabilizing the spontaneous spin polarization in the Au nanoparticles.
我们通过金 L(2)和 L(3)边缘的 X 射线磁圆二色性光谱证明，块状金在磁场中表现出温度无关的顺磁性。通过和和规则分析，我们在外磁场为 10T 的情况下得到了每个原子 1.3×10(-4)μB 的磁矩和 5d 轨道的 8.9×10(-6)顺磁磁化率。块状金的诱导顺磁性的特征是具有较大（约 30%）的轨道贡献。即使金原子形成纳米颗粒，这种轨道分量也得以保留，在稳定金纳米颗粒中的自发自旋极化方面发挥了重要作用。
