We experimentally prepared a ferromagnet with an L10-FeCo ordered structure by inserting a periodic buffer layer to suppress the B2 structural transition and to maintain the L10 structure. The sample was fabricated by utilizing a technique involving the deposition of alternating monoatomic layers using pulsed laser deposition (PLD). This technique was used to deposit a thin film of (7 ML-FeCo/3 ML-buffer)3, in which either Cu or Ni was utilized as buffer layer. We characterized the surface roughness, surface morphology, lattice structure, and magnetic properties of the specimens by RHEED, AFM, SR-XRD, and SQUID, respectively. As a result, we successfully confirmed the construction of the L10-FeCo superstructure with a periodic Ni buffer layer for the first time. Both the magnetic moment and magnetic anisotropy were also increased by replacing Cu with Ni.
