Inelastic Neutron Scattering Intensities of Ferromagnetic Cluster Spin Waves

Abstract

Inelastic neutron scattering (INS) is the key method for studying magnetic spectra. For ferromagnetic molecular nanomagnets the ferromagnetic cluster spin wave theory (FCSWT) exactly describes the low‐energy excitations from the ferromagnetic ground state. We provide a procedure starting from these molecular spin wave modes and ending with the experimentally observable INS spectra. The formulas for powder and single‐crystal spectra of isotropic and anisotropic ferromagnetic molecules are given. The INS interference pattern can be written in terms of “basis functions” fixed by the molecular geometry. We argue that this decomposition explicates the INS data when the spin wave modes are known and, vice versa, suggests a method to directly determine the quantum wavefunctions of the spin wave excitations based on the INS interference pattern. The calculation of INS observables is exemplified on three molecules: the Mn7 disc, the Mn10 supertetrahedron, and the Mn6 single molecule magnet.

Neutron Scattering in Coordination Chemistry

“…The final molecular magnet contribution to this volume is that of Prsa and Waldman, who show the power of spin-wave calculations in the study of Mnbased SMMs, complete with a review of the underlying theory. [7] Metal-organic frameworks (MOFs) are a recent addition to the field of coordination chemistry in the last few decades; these have rapidly moved to the forefront of materials research due to their record-breaking internal surface areas and high structural tunability, which promote their potential application in a number of energy-relevant fields. For instance, Queen et al have used neutron diffraction to investigate the hydrogen adsorption properties of a sodalite-type MOF, using D 2 as the adsorbate.…”

“…This type of experiment, which can be matched precisely to theoretical models, was truly impossible just a few years ago. The final molecular magnet contribution to this volume is that of Prsa and Waldman, who show the power of spin‐wave calculations in the study of Mn‐based SMMs, complete with a review of the underlying theory …”

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

“…This technique is now gaining importance as it provides unique insights into the physics of diverse spin clusters [19,[21][22][23][24][25]. Although it was argued that the powder-averaged intensity in principle contains all relevant information (with respect to pure magnetic scattering), in practice 4D-INS spectra facilitate the extraction of such information [26].…”