Symmetry-induced universal momentum-transfer dependencies for inelastic neutron scattering on anisotropic spin clusters

Article

关键词: MOLECULAR NANOMAGNETS;    DYNAMICS;    CHLORIDE;   

DOI  :  10.1103/PhysRevB.104.014416

来源: SCIE

【 摘 要 】

Inelastic neutron scattering (INS) is a key method for studying magnetic excitations in spin systems, including molecular spin clusters. The method has significantly advanced in recent years and now permits us to probe the scattering intensity as a function of the energy transfer and the momentum-transfer vector Q. It was recently shown that high molecular symmetry facilitates the analysis of spectra. Point-group symmetry imposes selection rules in isotropic as well as anisotropic spin models. Furthermore, the Q dependence of the INS intensity may be completely determined by the point-group symmetry of the states involved in a transition, thereby affording a clear separation of dynamics (energies, transition strengths) and geometrical features (Q dependencies). This paper addresses this issue for anisotropic spin models. We identify several cases where the Q dependence is completely fixed by the point-group symmetry. For six- and eight-membered planar spin rings and two polyhedra (the cube and the icosahedron), we tabulate and plot the corresponding powder-averaged universal intensity functions. The outlined formalism straightforwardly applies to other highly symmetric systems and should be useful for future analyses of INS spectra by focusing on those features that contain information on either spin dynamics or the point-group symmetry of states.

【 授权许可】

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