We report on the observations of spontaneous magnetic moments in the normal as well as in the superconducting states of a 9 nm Sn nanoparticle assembly, through X-ray diffraction, magnetization, ac magnetic susceptibility, and neutron diffraction measurements. The saturation magnetization reaches an unexpectedly large value of 1.04 emu/g at 5 K, with a temperature profile that can be described by Bloch's law with an exponent of b = 1.8. A magnetic moment of 〈μZ〉 = 0.38 μB develops after cooling from 260 to 4 K. Superconductivity develops below TC = 3.98 K, which is 7 % higher than the TC = 3.72 K of bulk Sn. Surprisingly, an addition magnetic moment of 〈μZ〉 = 0.05 μB develops upon entering the superconducting state.
- Sn nanoparticle