For the study of ferromagnetic materials which are compatible with group-IV semiconductor spintronics, we demonstrate control properties Heusler-alloy Fe3-xMnxSi epitaxially grown on Ge(111) by tuning Mn composition x. Interestingly, obtain L2(1)-ordered structures even for nonstoichiometric atomic compositions. The Curie temperature epilayers x approximately 0.6 exceeds 300 K. Theoretical calculations indicate that electronic alloys become half-metallic 0.75 < or = 1.5. We discuss...

The hydrogen treatment of the Nd-Fe-B alloy ingots was found to produce magnet powders with good magnetic properties. Typical properties these are as follows; 4πIs = 9.5 kG, Br 7.7 iHc 9.4 kOe, and (BH)max 12.2 MGOe. Microstructural studies showed that they made fine crystalline grains ∼0.3 μm diameter in individual powder not necessarily enclosed boundary phase(s), which is quite different from previously known magnets, i.e., sintered (the nucleation type magnet) or amorphous ribbon pinning...

The microstructures of anisotropic Nd-Fe-Co-B-(Ga, or Zr) magnet powders produced by the hydrogenation-decomposition-desorption-recombination (HDDR) process and resulting crystallographic c-axis orientation Nd2(Fe,Co)14B crystals in powder particles have been studied. It was found that consist fine size about 0.3 μm, any boundary-layer phase between crystalline grains is almost absent. morphology same as isotropic HDDR process. In powders, it there a strong correlation among axes, b c axes...

The surface treatment with Tb-vapor sorption improves the magnetic properties of small-sized magnets. Microstructure Tb-treated magnets was investigated by transmission electron microscopy (TEM). By applying Tb-treatment, diffusion Tb through grain boundaries occurred even inside magnets, and then a thin continuous wetting-layer phase formed at between Nd2Fe14B grains. results suggest that formation leads to improvement in properties.

The chemical bonding structure of ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) composite films prepared by pulsed laser deposition was examined near-edge X-ray absorption fine-structure (NEXAFS), photoemission, and Fourier transform infrared (FTIR) spectroscopies. An intense sp3-CH peak observed in the FTIR spectrum. This implies that originates from grain boundaries between UNCD crystallites, wherein dangling bonds are terminated with hydrogen atoms. presence an...

Ferromagnetic Fe3Si thin films with an extremely smooth surface morphology can be epitaxially grown on Si(111) at room temperature by facing target direct-current sputtering. The epitaxial relationship is Fe3Si(111)‖Si(111) Fe3Si[11¯0]‖Si[1¯10]. By the application of extinction rule x-ray diffraction, generated was confirmed to possess a B2 structure and not DO3 one. film showed saturation magnetization value 960emu∕cm3, which slightly lower than that bulk DO3-Fe3Si. It observed easy axis...

The spectral absorption properties of ultrananocrystalline diamond (UNCD)/amorphous carbon composite films grown by pulsed laser deposition with graphite were experimentally investigated. indirect optical band gaps estimated from the spectrum 1.0 eV and approximately 5.65 eV, which correspond to those for amorphous surrounding UNCDs themselves, respectively. In addition, revealed a direct gap having value 2.2 eV. One probable origin can be presence grain boundaries between since they are...

The complex permittivity, permeability and electromagnetic (EM) wave absorption properties have been investigated for resin compacts containing 75 wt% composite powders of α-Fe/C(a) Fe2B/C(a). real imaginary parts ( εr') relative permittivity the composites remained almost constant in 0.05–20.05 GHz range. part (μr') exhibited a wide peak 1–9 range 2–18 Both good EM (RL < −20 dB) 4.4–8.3 with an absorber thickness 1.9–3.4 mm, 7.5–16 1.2–2.2 respectively.

Amorphous iron silicide was reported to be semiconducting as well β-FeSi2, and it has received considerable attention from both the physical engineering points of view. However, there have been few studies its basic properties are still unknown. We could grow nanocrystalline disilicide thin films by pulsed-laser deposition using an FeSi2 target. They consist crystallites with diameters ranging 3 5 nm. The carrier density mobility at 300 K were 1.5×1019 cm−3 35 cm/V s, respectively.

Summary Behaviours of constituent elements in the Nd‐Fe‐B sintered magnets improved by Tb‐metal vapour sorption have been investigated using an analytical transmission microscopy. It was found that a triple junction grain boundaries consists fine Nd‐O crystalline and amorphous phase. The energy dispersive X‐ray spectroscopy (EDS) analysis showed phase mainly Co, Nd Tb. Tb‐treatment causes formation Co‐Nd(Tb) wetting‐layer which wraps each 2 Fe 14 B grain. results suggest wrapped structure...

We have investigated local element distributions in a Dy-doped Nd 2 Fe 14 B hot-deformed magnet by atomic-column resolution chemical mapping using an X-ray energy-dispersive spectrometer (XEDS) attached to aberration-corrected scanning transmission electron microscope (Cs-corrected STEM). The positions of the and Dy atomic columns were visualized XEDS maps. substitution was limited surface layer 2–3 unit cells thick grains, atoms preferentially occupied 4f-Nd sites B. These results provide...

Changes in microstructure of Nd–Fe–Co–B–Zr alloy powder during the hydrogenation-decomposition-desorption-recombination (HDDR) process have been investigated detail by transmission electron microscopy (TEM). It was found that microstructural changes HDDR start with formation cellular NdH2 and α-(Fe, Co) at a temperature between 933 973 K. The starting is about 50 K higher than Nd–Fe–B ternary system. By further annealing K, colonies rod-shaped spherical grains grow, embedded matrix....

The authors succeeded in preparing high-crystal-quality β-FeSi2 as-deposited film emitting a photoluminescence spectrum strong intensity. density of the nonradiative center at interface and remained low by depositing Cu-treated Si layer such as amorphous Si. recrystallization during deposition contributed to improving β-FeSi2∕Si crystallinity film.

Ion-beam-synthesized (IBS) β-FeSi 2 /Si(100) heterojunctions were observed by transmission electron microscopy (TEM) and atomic force (AFM). Clear epitaxial growth of on Si(111) large crystal domains laterally grown the surface demonstrated in Al-doped samples. The optical processes near heterojunction examined photoluminescence spectra measured different configurations. due to Al doping was found be effective reducing density nonradiative recombination centers enhancing an electron-hole...

The effects of Nd2Fe14B grain size and Nd coating on the coercivity in sputter-deposited Nd-Fe-B/Nd thin films have been investigated order to gain an insight into mechanism Nd-Fe-B magnets. Highly textured particles were grown successfully MgO(100) single-crystal substrate with Mo underlayer. As layer thickness t NFB was decreased from 70 5 nm, H c increased gradually 6.5 16 kOe. By depositing overlayer onto these post-annealing at 500 °C, value further 17.5 kOe (t NFB=70 nm) 26.2 NFB=5...

The hydrogenation-decomposition-desorption-recombination (HDDR) process is a unique method to produce anisotropic Nd/sub 2/Fe/sub 14/B-based magnet powder for bonded application. In this study, we studied the effect of appending intermediate Ar (IA) treatment, i.e., hydrogenated materials are annealed under an atmosphere before evacuation treatment in HDDR process, on magnetic properties powder. It was found that IA very effective enhance anisotropy optimum made from processed 12.6/Fe/sub...

Fe3Si/FeSi2 superlattices were prepared on Si(111) at two deposition rates by facing target direct-current sputtering. For the of 2.0 nm/min for Fe3Si and 1.3 FeSi2, layers nonoriented. On other hand, half-deposition rates, epitaxially grown not only but also up to top layer across FeSi2 layers. The antiferromagnetic interlayer coupling between was induced in epitaxial superlattices, whereas it disappeared nonepitaxial superlattices. regular accumulation highly oriented is crucial induction.

The atomic arrangements of short-range order (SRO) in two Al-rich γ-TiAl alloys with 62.5 and 60.0at.%Al respectively have been investigated by high-resolution transmission electron microscopy image processing. For both alloys, SRO structures are formed Ti-rich (002) layers the L10 ordered matrix, course phase transformation from Al5 Ti3 long-period superstructure at lower temperatures to h-Al2 Ti higher temperatures. composed three types cluster: Ti4 Al type (square shaped), (fat rhombus...