Journal of Applied Physics 131, 105102 (2022)
“Tuning of Curie temperature in Mn5Ge3 films”.
Y. Xie, M. Birowska, H. Simon Funk, I. A.Fischer, D. Schwarz, J. Schulze, Y.-J. Zeng, M. Helm, S. Zhou, S. Prucnal
Abstract:
We report a change in the structural and magnetic properties of epitaxial Mn$_5$Ge$_3$ on a Ge-on-Si (111) substrate by applying strain engineering through ms-range flashlamp annealing (FLA). X-ray diffraction results demonstrate that during FLA for 20 ms, the formation of nonmagnetic Mn$_x$Ge$_y$ secondary phases is fully suppressed, while the in-plane expansion of the lattice increases with increasing annealing temperature. Temperature-dependent magnetization results indicate that the Curie temperature of Mn5Ge3 rises from 287 K in the as-prepared sample to above 400 K after FLA, making Mn5Ge3 an attractive material for spintronics. Experimental results together with theoretical Monte Carlo simulations allow us to conclude that the expansion of the in-plane lattice causes the increase of the Curie temperature due to enhancement of the ferromagnetic interaction between Mn atoms.