Modification of the ferromagnetic properties of Si$_{1-x}$Mn$_{x}$ thin films synthesized by pulsed laser deposition with a variation in the buffer-gas pressure

A series of thin films of Si$_{1-x}$Mn$_{x}$ alloys with a thickness from 50 to 100 nm grown by pulsed laser deposition on an Al$_2$O$_3$ substrate in vacuum and in an argon atmosphere is investigated. The significant effect of the buffer-gas pressure in the sputtering chamber on the structural and magnetic homogeneity of the obtained films is shown. The conditions for the formation of a ferromagnetic phase with a high Curie temperature ( $>$ 300 K) in the samples are studied. With the use of the Langmuir probe method, the threshold of ablation of a MnSi target by second harmonic radiation ($\lambda$ = 532 nm) of a Nd:YAG $Q$-switch laser is determined. The time-of-flight curves for the plume ions are obtained with a change in the energy density at the target and argon pressure in the sputtering chamber. A nonmonotonic dependence of the probe time-of-flight signal amplitude on the argon pressure is established for high-energy particles of the plume.