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We present a comparative study of the anomalous Hall effect (AHE) and of the transverse Kerr effect (TKE) in the nonstoichiometric alloys. The data on AHE and TKE are consistent with each other and clearly indicate the intrinsic above room-temperature ferromagnetic order in the studied samples. We argue that this order is not produced by the phase segregation effects, but rather has a global character, while even a small level of the nonstoichiometry in alloys drastically changes their magnetic, electrical, optical and magneto-optical properties as compared to those of the stoichiometric manganese monosilicide MnSi. We propose a qualitative explanation of the obtained experimental results in the frame of the model of defect-induced ferromagnetic order using the first-principles calculations of the electronic and magnetic structure of the system.

Absence of anomalous Nernst effect in spin Seebeck effect of Pt/YIG AIP Advances 6, 015018 (2016); 10.1063/1.4941340Dual resonant structure for energy harvesting from random vibration sources at low frequency AIP Advances 6, 015019 (2016) The results of a comprehensive study of magnetic, magneto-transport and structural properties of nonstoichiometric Mn x Si 1-x (x≈0.51-0.52) films grown by the Pulsed Laser Deposition (PLD) technique onto Al 2 O 3 (0001) single crystal substrates at T = 340 • C are present. A highlight of used PLD method is the non-conventional ("shadow") geometry with Kr as a scattering gas during the sample growth. It is found that the films exhibit high-temperature (HT) ferromagnetism (FM) with the Curie temperature T C ∼ 370 K accompanied by positive sign anomalous Hall effect (AHE); they also reveal the polycrystalline structure with unusual distribution of grains in size and shape. It is established that HT FM order is originated from the bottom interfacial self-organizing nanocrystalline layer. The upper layer adopted columnar structure with the lateral grain size ≥ 50 nm, possesses low temperature (LT) type of FM order with T c

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A set of thin film Mn x Si 1−x alloy samples with different manganese concentration x ≈ 0.44 − 0.63 grown by the pulsed laser deposition (PLD) method onto the Al 2 O 3 (0001) substrate was investigated in the temperature range 4 − 300 K using ferromagnetic resonance (FMR) measurements in the wide range of frequencies ( f = 7 − 60 GHz) and magnetic fields (H = 0 − 30 kOe). For samples with x ≈ 0.52 − 0.55, FMR data show clear evidence of ferromagnetism with high Curie temperatures T C ∼ 300 K. These samples demonstrate complex and unusual character of magnetic anisotropy described in the frame of phenomenological model as a combination of the essential second order easy plane anisotropy contribution and the additional forth order uniaxial anisotropy contribution with easy direction normal to the film plane. We explain the obtained results by a polycrystalline (mosaic) structure of the films caused by the film-substrate lattice mismatch. The existence of extra strains at the crystallite boundaries leads to an essential inhomogeneous magnetic anisotropy in the film plane.