Modification of the Ferromagnetic Properties of Si_1–xMn_x Thin Films Synthesized by Pulsed Laser Deposition with a Variation in the Buffer-Gas Pressure

A series of thin films of Si_1–xMn_x alloys with a thickness from 50 to 100 nm grown by pulsed laser deposition on an Al₂O₃ 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 (λ = 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.