Fabrication of monocrystalline CоFeMnSi Heusler alloy film on MgO substrate

The pulsed laser deposition method has been used for the growth of CoFeMnSi thin films on an atomically smooth MgO (100) substrate, which is of interest in spintronics applications. Optimization of substrate temperature, laser energy, and pulse frequency allowed for the formation of continuous, uniformly thick monocrystalline films without subsequent high-temperature annealing process. Electron microscopy and diffraction analysis of cross-sectional specimens of the grown films revealed that they exhibit a perfect cubic crystalline atomic structure. It was demonstrated that the atomic planes of CoFeMnSi $\{202\}$ align with the parallel planes of the MgO substrate $\{020\}$, and a misfit of 4.65% between their interplanar spacings relaxes with the formation of misfit dislocations at the interface.