The operation of a micro-pump system driven by a magnetoelastic polymeric membrane developed at Texas A&M University is analyzed by numerical simulations. Unsteady, incompressible NavierStokes equations in a moving boundary system are solved by a spectral element methodology, employing an Arbitrary Lagrangian Eulerian (ALE) formulation on unstructured meshes. The performance of the micro-pump i...

Spin dynamics controlled by magnetoelastic coupling and applied electric fields might play a vital role in future developments of magnonics, i.e., the exploitation of spin waves for the transmission and processing of information. We have performed broadband spin-wave spectroscopy on a magnetostrictive CoFeB alloy grown on a ferrolectric BaTiO3 substrate causing elastic strain with a quasi-perio...

We combined Raman and infrared vibrational spectroscopies with complementary lattice dynamics calculations and magnetization measurements to reveal the dynamic aspects of charge-lattice-spin coupling in Co[N(CN)2]2. Our work uncovers electron-phonon coupling as a magnetic field-driven avoided crossing of the low-lying Co2+ electronic excitation with two ligand phonons and a magnetoelastic effec...

Inelastic neutron scattering was used to systematically investigate the spin-wave excitations ~magnons! in ferromagnetic manganese perovskites. In spite of the large differences in the Curie temperatures (TC’s! of different manganites, their low-temperature spin waves have very similar dispersions with the zone-boundary magnon softening and broadening that cannot be explained by the canonical d...

We have studied the exchange anisotropy of ferromagnetic Fe films grown on antiferromagnetic FeF2 single crystals. The behavior of the hysteresis loops of the Fe above and below the Néel temperature TN of FeF2 indicates a 90° rotation of the ferromagnetic easy axis due to the antiferromagnetic ordering. By examining the Fe hysteresis loops together with the FeF2 susceptibility behavior we infer...

By including the full pressure tensor dynamics in a fluid plasma model, we show that a sheared velocity field can provide an effective mechanism that makes the initial isotropic pressure nongyrotropic. This is distinct from the usual gyrotropic anisotropy related to the fluid compressibility and usually accounted for in double-adiabatic models. We determine the time evolution of the pressure ag...

2014The magnetic excitations of the antiferromagnetic compound ErCu (cubic CsCl structure) have been studied by inelastic neutron scattering at 4.3 K. The data are analysed within a generalized susceptibility model, taking into account the crystal field Hamiltonian and anisotropic bilinear exchange. Interactions up to the fourth neighbours seem sufficient to describe the dispersion relations; t...