Ames Laboratory, Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA.
J Phys Condens Matter. 2010 Nov 24;22(46):466001. doi: 10.1088/0953-8984/22/46/466001. Epub 2010 Oct 29.
Inelastic neutron scattering (INS) in variable magnetic field and high-field magnetization measurements in the millikelvin temperature range were performed to gain insight into the low-energy magnetic excitation spectrum and the field-induced level crossings in the molecular spin cluster {Cr(8)}-cubane. These complementary techniques provide consistent estimates of the lowest level-crossing field. The overall features of the experimental data are explained using an isotropic Heisenberg model, based on three distinct exchange interactions linking the eight Cr(III) paramagnetic centers (spins s = 3/2), that is supplemented with a relatively large molecular magnetic anisotropy term for the lowest S = 1 multiplet. It is noted that the existence of the anisotropy is clearly evident from the magnetic field dependence of the excitations in the INS measurements, while the magnetization measurements are not sensitive to its effects.
变磁场下的非弹性中子散射（INS）和毫开尔文温度范围内的高场磁化强度测量，旨在深入了解分子自旋簇{Cr(8)}立方烷中的低能磁激发谱和场诱导能级交叉。这些互补技术提供了最低能级交叉场的一致估计。实验数据的整体特征采用基于三个不同的交换相互作用的各向同性海森堡模型来解释，该模型连接了八个 Cr(III)顺磁中心（自旋 s = 3/2），并补充了最低 S = 1 多重态的相对较大的分子磁各向异性项。值得注意的是，从 INS 测量中的激发对磁场的依赖性可以明显看出各向异性的存在，而磁化强度测量对其影响不敏感。
