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The magnetic properties of the Cr2Ge2Te6 monolayer – an important two-dimensional (2D) ferromagnetic (FM) material – are systematically investigated on the basis of ab initio electronic structure calculations within density functional theory (DFT). For these purposes we construct a minimal tight-binding model in the basis of maximally localized Wannier functions, which describes the behavior of the magnetic Cr 3d, Ge 4p, and Te 5p electrons. This model allows us to rationalize the results of conventional DFT calculations at the microscopic level. We explore the abilities of different techniques, including the Green's function perturbation theory and constraint calculations with an external magnetic field, for the analysis of magnetic interactions, that allow us to decompose these interactions in terms of partial contributions coming from different atomic sites. We argue that, although the magnetism of Cr2Ge2Te6 originates from the Hund's rule effects in the partially filled Cr 3d shell, the contributions of the ligand – and particularly Te 5p – states are crucially important and have a significant effect on the behavior of isotropic exchange interactions, magnetocrystalline anisotropy energy (MAE), and antisymmetric Dzyaloshinskii–Moriya (DM) interactions induced by an electric field. In particular, the Te 5p states increase dramatically the FM coupling and DM interactions between the Cr spins. They are also largely responsible for the behavior of MAE, manifesting themselves in non-Heisenberg type effects, which go beyond the scopes of the conventional Mermin–Wagner theorem for the analysis of 2D magnetism of Cr2Ge2Te6. [ABSTRACT FROM AUTHOR]

A two-dimensional ferromagnetic semiconductor Cr2Ge2Te6 (CGT) was recently found to possess extraordinary characteristics and has great potential in the emerging field of spintronics. Using first-principles calculations, we examined the stabilities of this layered system by studying the cleavage energies and phonon dispersion. The ferromagnetic ground state has an in-plane spin polarization and bandgaps of about 0.26 eV by Perdew-Burke-Ernzerhof-van der Waals and 0.91 eV by the Heyd-Scuseria-Ernzerhof functional. Furthermore, we employed strain engineering and an external electric field to control the electronic and magnetic properties. In addition, we studied the magnetic anisotropy energy as well as its modulation under the electric field. We predict the CGT monolayer to be the easy plane ferromagnet, and the perpendicular electric field could affect the ferromagnetic stability along different directions. Our obtained results provide guidance for the potential applications of monolayer CGT for magnetic nanodevices, spintronic, and straintronic applications. [ABSTRACT FROM AUTHOR]

Background: The aim of the study was to investigate the value of single nucleotide polymorphism array (SNP array) technology in the prenatal diagnosis., Methods: The variants in Xp22.31q27.1 region of 13 fetuses were analyzed by SNP array technology. Chromosome karyotype analysis was also performed for these fetuses and their parents., Results: Chromosome karyotype analysis found no obvious chromosomal abnormality at 400 bands resolution. Using SNP array technology, we found that all fetuses had mutations in Xp22.31q27.1 region, which was mainly Xp22.31 lesion (61.5%, 8/13) that contained 2 to 5 OMIM genes. Moreover, these mutations consisted of 7 cases of repetition and 6 cases of deletion. In addition, 9 variants were inherited from their mothers, 3 mutations were inherited from the father, and 1 variant was de novo., Conclusions: Compared to traditional analysis of chromosome karyotype, SNP-array technology can detect more chromosomal microdeletions and microduplications. SNP-array technology can act as a supplementary diagnostic method in clinical cytogenetic diagnosis.

The magnetic properties of the Cr2Ge2Te6 monolayer - an important two-dimensional (2D) ferromagnetic (FM) material - are systematically investigated on the basis of ab initio electronic structure calculations within density functional theory (DFT). For these purposes we construct a minimal tight-binding model in the basis of maximally localized Wannier functions, which describes the behavior of the magnetic Cr 3d, Ge 4p, and Te 5p electrons. This model allows us to rationalize the results of conventional DFT calculations at the microscopic level. We explore the abilities of different techniques, including the Green's function perturbation theory and constraint calculations with an external magnetic field, for the analysis of magnetic interactions, that allow us to decompose these interactions in terms of partial contributions coming from different atomic sites. We argue that, although the magnetism of Cr2Ge2Te6 originates from the Hund's rule effects in the partially filled Cr 3d shell, the contributions of the ligand - and particularly Te 5p - states are crucially important and have a significant effect on the behavior of isotropic exchange interactions, magnetocrystalline anisotropy energy (MAE), and antisymmetric Dzyaloshinskii-Moriya (DM) interactions induced by an electric field. In particular, the Te 5p states increase dramatically the FM coupling and DM interactions between the Cr spins. They are also largely responsible for the behavior of MAE, manifesting themselves in non-Heisenberg type effects, which go beyond the scopes of the conventional Mermin-Wagner theorem for the analysis of 2D magnetism of Cr2Ge2Te6.