Beyond a phenomenological description of magnetostriction
  We use ultrafast x-ray and electron diffraction to disentangle spin-lattice coupling of granular FePt in the time domain. The reduced dimensionality of single-crystalline FePt nanoparticles leads to strong coupling of magnetic order and a highly anisotropic three-dimensional lattice motion characterized by a- and b-axis expansion and c-axis contraction. The resulting increase of the FePt lattice tetragonality, the key quantity determining the energy barrier between opposite FePt magnetization orientations, persists for tens of picoseconds. These results suggest a novel approach to laser-assisted magnetic switching in future data storage applications. 
A. H. Reid, X. Shen, P. Maldonado, T. Chase, E. Jal, P. Granitzka, K.   Carva, R. K. Li, J. Li, L. Wu, T. Vecchione, T. Liu,...
cond-mat.mtrl-sci