Structural dynamics of a laser induced magnetic phase transition in FeRh

Full text: The interactions between magnetic, electronic and structural degrees of freedom in solid state systems both play a key role when it comes to understanding their fundamental properties and forms the basis for their use in technological devices. In this context the magnetic alloy FeRh displays an unusual phase transition with the magnetic order changing from antiferromagnetic to ferromagnetic simultaneously with a lattice expansion, which lends itself to a study of then interaction between magnetism and structure. The ultra-fast laser-induced dynamics of this transition has previously been studied by optical methods but we present the result of a time-resolved x-ray diffraction experiment in which we directly study the laser induced lattice dynamics in a FeRh thin-film. Additional measurements of the magneto optical Kerr effect on the same sample under similar conditions allow us to compare how the structure and magnetism evolve as a function of time after laser excitation. (author)