Microstructure and room temperature ferromagnetism of double-layered MnxGe1−xTe polycrystalline modified by the space-layer thickness

• Published in: Applied surface science Vol. 657; p. 159837
• Main Authors: Wu, Dingzhang, Lu, Chunjiang, He, Xinpeng, Duan, Xiaoxiao, Lv, Junhong, Lv, Xinze, Yang, Jie, Ke, Shaoying, Lin, Feng, Wang, Chong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2024
• Subjects: Curie temperature; Dilute magnetic semiconductor (DMS); Double-layer MnxGe1−xTe polycrystalline; Si space layer; Double-layer MnxGe1−xTe polycrystalline; Dilute magnetic semiconductor (DMS); Si space layer; Curie temperature
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.159837

[Display omitted] •The double-layer polycrystalline samples with high magnetic properties were successfully prepared through high quality, high-precision, and high-efficiency IBS technology.•The double-layer Mn1−xGexTe polycrystalline samples have higher Curie temperature (TC = 373.5 K) and magnetic properties than single- layer samples.•The double-layer polycrystalline sample has higher crystal quality, higher Ge content, and obvious quantum confinement effect, which are the reasons for its higher magnetic properties.•This research not only provides a solution to enhance the magnetic properties of nanoislands, but also further promotes its practical applications. Dilute magnetic semiconductor (DMS) nanomaterials have broad application prospects in spin electronics, but low Curie temperatures (TC) hinders their applications. In this work, MnxGe1−xTe (MGT) polycrystalline with a double-layer structure were fabricated on Si (100) substrates using ion beam sputtering. When compared to single-layer sample, the double-layer polycrystalline formed uneven stress distribution on the surface and preferred nucleation site, thus promoting the growth of the MGT polycrystalline. The saturation magnetization (MS) and remanent magnetization (MR) of double-layered polycrystalline were measured to be 4.43 × 10−5 emu/mm2 and 1.05 × 10−5 emu/mm2, respectively, and the TC reached 373.5 K. When comparing it to the single-layer sample, on the one hand, the double-layer sample shows enhanced magnetic properties and strain due to the increased Ge content. On the other hand, the quantum confinement effect and the relative strength of the Ge-Ge bond will affect the magnetic properties of the double-layer sample. In summary, the work not only provides a feasible way to improve the magnetic performance of DMS, but also improves the temperature application range of high-performance devices where polycrystalline are compatible with traditional complementary oxide metal (CMOS) technology.