Pratt F L, Blundell S J, Lancaster T, Baines C, Takagi S
ISIS Facility, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, United Kingdom.
Phys Rev Lett. 2006 Jun 23;96(24):247203. doi: 10.1103/PhysRevLett.96.247203. Epub 2006 Jun 19.
The organic radical-ion salt DEOCC-TCNQF4 contains linear chains of stacked molecules with significant Heisenberg antiferromagnet interactions along the chain and extremely weak interactions between the chains. Zero-field muSR has confirmed the absence of long-range magnetic order down to 20 mK and field-dependent muSR is found to be consistent with diffusive motion of the spin excitations. The anisotropic spin dynamics and the upper boundary for magnetic ordering temperature both indicate interchain magnetic coupling /J'/<7 mK. As the intrachain coupling J is 110 K, /J'/J/ is significantly less than 10(-4). This system therefore provides one of the most ideal examples of the one-dimensional S=1/2 Heisenberg antiferromagnet yet discovered.
有机自由基离子盐DEOCC-TCNQF4包含堆叠分子的线性链，沿链具有显著的海森堡反铁磁相互作用，而链间相互作用极弱。零场μ子自旋旋转（muSR）已证实，直至20 mK都不存在长程磁序，且发现场依赖型muSR与自旋激发的扩散运动一致。各向异性自旋动力学和磁有序温度的上限均表明链间磁耦合/J'/<7 mK。由于链内耦合J为110 K，/J'/J/显著小于10^(-4)。因此，该系统提供了迄今发现的一维S = 1/2海森堡反铁磁体最理想的例子之一。
