title: Mapping spatial and field dependence of magnetic domain memory by soft X-ray speckle metrology.
abstract: The occurrence of magnetic domain memory has been observed in ferromagnets, either induced by structural defects or by exchange couplings. Being able to quantify the amount of memory as a function of length scale, field and temperature is both of fundamental and technological importance. A technique has been refined to statistically quantify the magnetic domain memory in ferromagnetic thin films by using coherent soft-X-ray scattering metrology. This technique, based on cross-correlating magnetic speckle patterns, provides a unique way to map out the behavior of domain memory. Here, the details of our correlation method and the necessary treatment of the X-ray scattering images to extract spatial and field dependences in the memory information are reviewed. The resulting correlation maps, measured on [Co/Pd]IrMn multilayers, show how magnetic domain memory evolves at various spatial scales, as a function of the field magnitude throughout magnetization cycles, but also as a function of field cycling and of temperature. This technique can easily be applied to a wide variety of systems presenting memory effects, in soft and hard matter, and also to dynamical studies.
authors.affiliation: Physics Department, Brigham Young University, UT 84602, USA. kchesnel@byu.edu
authors.forename: K
authors.initials: K
authors.lastname: Chesnel
authors.forename: J
authors.initials: J
authors.lastname: Nelson
authors.forename: B
authors.initials: B
authors.lastname: Wilcken
authors.forename: S D
authors.initials: SD
authors.lastname: Kevan