Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
J Phys Condens Matter. 2011 Apr 27;23(16):164219. doi: 10.1088/0953-8984/23/16/164219. Epub 2011 Apr 6.
The rare earth pyrochlore magnet Yb(2)Ti(2)O(7) is among a handful of materials that apparently exhibit no long range order down to the lowest explored temperatures and well below the Curie-Weiss temperature. Paramagnetic neutron scattering on a single crystal sample has revealed the presence of anisotropic correlations and recent work has led to the proposal of a detailed microscopic Hamiltonian for this material involving significantly anisotropic exchange. In this paper, we compute the local sublattice susceptibility of Yb(2)Ti(2)O(7) from the proposed model and compare with the measurements of Cao et al (2009 Phys. Rev. Lett. 103 056402), finding quite good agreement. In contrast, a model with only isotropic exchange and long range magnetostatic dipolar interactions gives rise to a local susceptibility that is inconsistent with the data.
Yb(2)Ti(2)O(7) 是一种稀土烧绿石磁体,它是少数几种显然在最低探测温度甚至远低于居里-外斯温度以下都没有长程有序的材料之一。对单晶样品的顺磁中子散射揭示了各向异性相关的存在,最近的工作提出了一个详细的微观哈密顿量,该模型涉及到显著各向异性的交换。在本文中,我们从所提出的模型计算了 Yb(2)Ti(2)O(7) 的局域子晶格磁化率,并与 Cao 等人(2009 年 Phys. Rev. Lett. 103 056402)的测量结果进行了比较,发现非常好的一致性。相比之下,只有各向同性交换和长程静磁偶极子相互作用的模型会导致与数据不一致的局域磁化率。