Fabrication of fully-epitaxial co-{{{2}}}mnsi/ag/co-{{{2}}}mnsi giant magnetoresistive devices by elevated temperature deposition

(001)-oriented epitaxial Co-{{2}}MnSi (CMS) films were grown by elevating the substrate temperature during deposition instead of a conventional post-annealing process. The CMS film deposited at 250^\circ C showed a very flat surface morphology, large saturation magnetization, and a highly {\rm L2}-{{1}}-ordered crystal structure. A CMS/Ag/CMS giant-magnetoresistive device with CMS layers grown at 250^\circ C showed the high magnetoresistance ratio (33%) at room temperature. This ratio was close to that realized in the case of samples fabricated using post-annealing at 500-550 ^\circ C. The elevated temperature deposition for the Heusler electrodes is a promising method to fabricate a practical magnetic read sensor for next generation hard disc drives without high temperature annealing process over 300^\circC.