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Silicon-vacancy (SiV) centers were produced in single crystalline diamond (SCD) and ultrananocrystalline diamond (UNCD) nanostructures via Si ion implantation or in situ Si doping. SiV-embedded UNCD (SiV-UNCD) was fabricated by both top-down and bottom-up methods. The spectral properties of the SiV centers, including the zero phonon line (ZPL) width and decay time, were investigated in the SCD and UNCD nanostructures. All the SiV-UNCD nanostructures showed bright emission regardless of the preparation method. However, the decay time of the SiV centers was affected by the synthesis procedure. A SiV decay time of τ ∼ 0.19 ns was observed for UNCD nanostructures formed by in situ doping, whereas the SiV decay time was ∼0.43 ns for SiV-UNCD clusters prepared by Si ion implantation into UNCD deposited on Ti/sapphire substrates. The ultrasonication of UNCD clusters on Ti/sapphire pyramids produced bright SiV-UNCD nanoclusters with sizes of ∼50 nm, a ZPL width of 13.5 nm, and a decay time of 0.35 ns, suggesting promising potential in bioimaging applications. SiV-containing SCD (type Ia or type IIa) showed enhanced SiV spectral properties with a ZPL width of 6.08 nm and longer decay time of 1.3 ns.Silicon-vacancy (SiV) centers were produced in single crystalline diamond (SCD) and ultrananocrystalline diamond (UNCD) nanostructures via Si ion implantation or in situ Si doping. SiV-embedded UNCD (SiV-UNCD) was fabricated by both top-down and bottom-up methods. The spectral properties of the SiV centers, including the zero phonon line (ZPL) width and decay time, were investigated in the SCD and UNCD nanostructures. All the SiV-UNCD nanostructures showed bright emission regardless of the preparation method. However, the decay time of the SiV centers was affected by the synthesis procedure. A SiV decay time of τ ∼ 0.19 ns was observed for UNCD nanostructures formed by in situ doping, whereas the SiV decay time was ∼0.43 ns for SiV-UNCD clusters prepared by Si ion implantation into UNCD deposited on Ti/sapphire substrates. The ultrasonication of UNCD clusters on Ti/sapphire pyramids produced bright SiV-UNCD nanoclusters with sizes of ∼50 nm, a ZPL width of 13.5 nm, and a decay time of 0.35 ns, suggesting ...

Ion implantation is used to create nanodiamonds (NDs) with embedded magnetic ions for use in a wide range of biological and medical applications; however, the effectiveness of this process depends heavily on separating magnetic NDs from nonmagnetic ones. In this study, we use secondary ion mass spectrometry to verify the implantation of magnetic ions in NDs and the success of separation. When applied to a series of NDs with embedded iron or manganese ions, the sorting tool used in this study proved highly effective in selecting magnetic NDs. Besides, multienergy ion implantation and precise thickness control of NDs coating on the silicon wafer were suggested to improve this technology.

We report the optical and electrical properties of high-dose (1015–1017 ions/cm2) Mn-ion implanted ultrananocrystalline diamond (Mn-UNCD) films. Mn-ion implantation and post-annealing of UNCD films lead to the formation of Mn-related color centers, characterized in Mn-UNCD films by their zero phonon line emissions at 621.2 nm and phonon sidebands at 611.2 nm and 630.3 nm. Raman spectra of Mn-UNCD films indicated amorphization via high-dose Mn-ion implantation and that the annealing process results in graphitization of the films. The Mn-UNCD film implanted with the Mn-ion dose of 1017 ions/cm2 exhibits a conductivity of 122.25 (Ω cm)−1, as well as enhanced field electron emission (FEE) properties such as a turn-on field of 10.67 V/μm and a FEE current density of 0.85 mA/cm2.

We have grown epitaxial spinel ferrite thin films of (Mn,Zn) Fe2O4 and CoFe2O4 on (100) and (110) SrTiO3 and MgAl2O4 buffered by spinel structure buffer layers. High quality spinel ferrite films were grown at 400 °C on buffer layers that were grown at 600 °C and postannealed at 1000 °C. Although (Mn,Zn) Fe2O4 grown directly on SrTiO3 and MgAl2O4 shows mediocre structural and magnetic properties, ferrite films grown on (100) and (110) SrTiO3 and MgAl2O4 buffered with CoCr2O4 exhibit excellent crystallinity and bulk saturation magnetization values, thus indicating the importance of lattice match and structural similarity between the film and the immediately underlying layer.

Ferromagnetic GeMn was prepared by Mn implantation followed by ion beam-induced epitaxial crystallization annealing. The damage caused by Mn implantation was repaired by subsequent helium ion irradiation. Various structural analyses were performed and Mn ions were found to incorporate uniformly into the Ge lattice without the formation of any secondary phases. The remnant magnetic moment exhibited room temperature ferromagnetism. Anomalous Hall effect and field dependent magnetization were measured at the same time at room temperature indicating spin polarized free carrier transport. Additional measurement using x-ray magnetic circular dichroism also revealed that the carriers were spin-polarized.