Keren A, Gardner J S, Ehlers G, Fukaya A, Segal E, Uemura Y J
Department of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Phys Rev Lett. 2004 Mar 12;92(10):107204. doi: 10.1103/PhysRevLett.92.107204.
Investigations of the spin dynamics of the geometrically frustrated pyrochlore (Tb(p)Y(1-p))2Ti2O7, using muon spin relaxation and neutron spin echo, as a function of magnetic coverage p, have been carried out. Our major finding is that paramagnetic fluctuations prevail as T-->0 for all values of p, and that they are sensitive to dilution, indicating a cooperative spin motion. However, the percolation threshold pc is not a critical point for the fluctuations. We also find that the low temperature spectral density has a 1/f behavior, and that dilution slows down the spin fluctuations.
利用μ子自旋弛豫和中子自旋回波技术，对几何阻挫的烧绿石（Tb(p)Y(1 - p))2Ti2O7的自旋动力学随磁覆盖度p的变化进行了研究。我们的主要发现是，对于所有p值，当T→0时顺磁涨落占主导，且它们对稀释敏感，表明存在协同自旋运动。然而，渗流阈值pc并非涨落的临界点。我们还发现低温谱密度具有1/f行为，且稀释会减缓自旋涨落。
