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To date, research on defect-induced magnetism in SiC has been conducted to clarify the relationship between the ferromagnetic signal and the carrier concentration. It has been experimentally proven that there is an interaction between the d 0 magnetic moment and the hole carrier in p-type 4H-SiC. However, for n-type SiC, the existing theoretical predictions are insufficient to explain the variation in magnetization with the doping concentration. To solve this problem, we prepared 4H-SiC epitaxial layers with different nitrogen doping concentrations and introduced defects by ion implantation. By measuring and analyzing the magnetic properties, we found that the ferromagnetic composition depends on both the implantation dose and the doping concentration. By performing first-principles calculations, we studied the magnetic moments and interactions of defects with different charge states, which is related to defect-induced ferromagnetism. These defects include not only the paramagnetic centers reported in previous studies, such as silicon vacancies and divacancies, but also the N C V Si complex defect of recent interest, which are indicated by positron annihilation experiments. Combining experimental observations with theoretical calculations, we explained the relationship between magnetic properties and the nitrogen doping concentration in the epitaxial samples. Our research will help us to better understand the physical mechanism of defect-induced magnetism in doped semiconductors and provide a potential platform for the control of defect-induced magnetism by carrier density modulation and the fabrication of SiC spintronic devices without transition metals. [ABSTRACT FROM AUTHOR]

We present the magnetic, transport, and structural properties of GaMnP with different Mn concentrations prepared by ion implantation and pulsed laser annealing. The Curie temperature increases with Mn concentration and the samples show in-plane magnetic anisotropy due to the in-plane compressive strain in the GaMnP layer. Anomalous Hall effect and negative magnetoresistance are observed, indicating the carrier mediated nature of the ferromagnetism in GaMnP. According to the micro-Raman spectroscopy data after pulsed laser annealing, the implanted layer has been fully recrystallized and the carrier concentration (hole) increases with Mn concentration. [ABSTRACT FROM AUTHOR]

Ferromagnetism can occur in wide-band gap semiconductors as well as in carbon-based materials when specific defects are introduced. It is thus desirable to establish a direct relation between the defects and the resulting ferromagnetism. Here, we contribute to revealing the origin of defect-induced ferromagnetism using SiC as a prototypical example. We show that the long-range ferromagnetic coupling can be attributed to the p electrons of the nearest-neighbor carbon atoms around the VSiVC divacancies. Thus, the ferromagnetism is traced down to its microscopic electronic origin. [ABSTRACT FROM AUTHOR]

• Exchange bias effect and room temperature ferromagnetism are observed in β - Ga 2 O 3 :Mn. • The single domain and core-shell models are used to study the exchange bias system. • A new explanation is proposed for the origin of the observed ferromagnetism. In this manuscript, the structural and magnetic properties of a 55Mn+ ion-implanted unintentionally doped β - Ga 2 O 3 single crystal are investigated. The implanted Mn + ions cause crystalline degeneration due to the formation of defects in the surface of the substrate. Room temperature ferromagnetism (FM) is observed in the samples with implantation doses of 5 × 10 14 cm - 2 , 1 × 10 15 cm - 2 and 5 × 10 15 cm - 2 . The zero-field-cooled (ZFC)/field-cooled (FC) measurement of magnetization reveals that the ion implantation process induces an antiferromagnetic (AFM) phase. The temperature evolution of the remanence asymmetry ( M E ) demonstrates the typical behavior of the exchange bias effect due to the coexistence of FM and AFM phases. Based on the distribution of Mn + ions and defects and the relationship between the remanence asymmetry ( M E ) and the exchange bias field ( H E ), the single domain and core-shell models are used to investigate the exchange bias system. The formation mechanism of the ferromagnetic order is briefly discussed, which is rather different from the one corresponding to the bound magnetic polaron (BMP) model. [ABSTRACT FROM AUTHOR]