Ge_xSi_1−x virtual-layer enhanced ferromagnetism in self-assembled Mn_0.06Ge_0.94 quantum dots grown on Si wafers by molecular beam epitaxy

Abstract

The ferromagnetism of MnGe QDs grown on GeSi VS will markedly increase by increasing the Ge composition of GeSi VS.

Microstructure and Ferromagnetism of Mn0.05Ge0.95 Quantum Dots/Graphene Heterostructures for Spintronic Devices

“…24−26 Conventional Mn x Ge 1−x DMSs tend to use single-crystal silicon as a substrate and rely on a small lattice mismatch between germanium and silicon to form Mn x Ge 1−x QDs after epitaxial growth. 27,28 Unfortunately, while single-crystal silicon substrates can be adapted to be compatible with silicon-based microelectronics, the small lattice mismatch of silicon− germanium makes Mn tend to exist in Ge in the form of manganese-poor/rich regions, which leads to the appearance of intermetallic precipitates and limits the application of Mn x Ge 1−x QDs in spintronic devices. 29,30 Therefore, a new zero-dimensional/two-dimensional heterostructure is needed to make Mn x Ge 1−x QDs meet the demand for spintronic device applications.…”

“…Conventional Mn x Ge 1– x DMSs tend to use single-crystal silicon as a substrate and rely on a small lattice mismatch between germanium and silicon to form Mn x Ge 1– x QDs after epitaxial growth. , Unfortunately, while single-crystal silicon substrates can be adapted to be compatible with silicon-based microelectronics, the small lattice mismatch of silicon–germanium makes Mn tend to exist in Ge in the form of manganese-poor/rich regions, which leads to the appearance of intermetallic precipitates and limits the application of Mn x Ge 1– x QDs in spintronic devices. , Therefore, a new zero-dimensional/two-dimensional heterostructure is needed to make Mn x Ge 1– x QDs meet the demand for spintronic device applications. Graphene, a two-dimensional material composed of sp 2 hybridized carbon atoms, relies on an extremely high carrier mobility and a long spin-diffusion length for applications in spintronic devices. , As an ideal two-dimensional material, graphene is less affected by lattice distortion during the epitaxial growth of Mn x Ge 1– x QDs due to the lack of dangling bonds on the surface, which can hinder the appearance of manganese-poor/rich regions and limit intermetallic precipitation.…”

Growth and Magnetism of MnxGe1−x Heteroepitaxial Quantum Dots Grown on Si Wafer by Molecular Beam Epitaxy

“…Room temperature ferromagnetism was reported in self-assembled Mn 0.05 Ge 0.95 quantum dots (QDs) [16] and pattern-assisted Mn x Ge 1−x nanowires [17]. Researchers hold high expectations for the ferromagnetic properties of MnGe QDs in recent years since QD is one of the excellent candidate structures for spin devices [18][19][20][21][22][23]. There are only a few reports on the study of the growth, morphology, and magnetism of MnGe QDs [18,19,22].…”