Magnetic anisotropy induced by crystal distortion in Ge1−xMnxTe/PbTe//KCl (001) ferromagnetic semiconductor layers

Abstract

Ferromagnetic resonance (FMR) study of magnetic anisotropy is presented for thin layers of IV-VI diluted magnetic semiconductor Ge1-xMnxTe with x=0.14 grown by molecular beam epitaxy (MBE) on KCl (001) substrate with a thin PbTe buffer. Analysis of the angular dependence of the FMR resonant field reveals that an easy magnetization axis is located near to the normal to the layer plane and is controlled by two crystal distortions present in these rhombohedral Ge1-xMnxTe layers: the ferroelectric distortion with the relative shift of cation and anion sub-lattices along the [111] crystal direction and the biaxial in-plane, compressive strain due to thermal mismatch.

Magnetic Skyrmionic Polarons

“…58 For a concentration x=5.4% of Mn, the measured band structure parameters are, m * =0.2, λ=3eVÅ, and J=0.11eV, that correspond to the following tightbinding parameters, t=0.53eV, t R =0.25eV and J=0.06eV obtained using a lattice constant a ∼ 6Å. 59 From these numbers, and comparing with the results presented in Figure 2 and…”

“…Recently soft X-ray ARPES on epitaxially grown thin films of Ge 1– x Mn x Te has been reported . For a concentration of x = 5.4% of Mn, the measured band structure parameters are m * = 0.2, λ = 3 eV·Å, and J = 0.11 eV, which correspond to the following tight-binding parameters, t = 0.53 eV, t R = 0.25 eV, and J = 0.06 eV obtained using a lattice constant a ≈ 6 Å . From these numbers, and comparing with the results presented in Figures and , we conclude that it is possible that magnetic skyrmionic polarons appear in Ge 1– x Mn x Te at very low densities and temperatures lower than 10 K. For a concentration of Mn ions of 5%, the magnetic skyrmionic polarons will be present up to rather large magnetic fields, >20 T. Recently obtained quasi-two-dimensional ferromagnetic materials − are expected to have a strong Rashba spin–orbit coupling and therefore are also good candidates to host magnetic skyrmionic polarons.…”

“…58 For a concentration x=5.4% of Mn, the measured band structure parameters are, m * =0.2, λ=3eVÅ, and J=0.11eV, that correspond to the following tightbinding parameters, t=0.53eV, t R =0.25eV and J=0.06eV obtained using a lattice constant a ∼ 6Å. 59 From these numbers, and comparing with the results presented in Figure 2 and Figure 3 we conclude that it is possible that magnetic skyrmionic polarons appear in Ge 1−x Mn x Te at very low densities and temperatures lower than 10K. For a concentration of Mn ions of 5% the magnetic skyrmionic polarons will be present up to rather large magnetic fields, >20T.…”