Structure and magnetic properties of sputtered (Nd,Dy)(Fe,Co,Nb,B) \u3csub\u3e5.5\u3c/sub\u3e/M (M = FeCo,Co) multilayer magnets

The magnetic properties of nanocomposite multilayer magnets of the (Nd,Dy)(Fe,Co,Nb,B) 5.5/M (M = Co,FeCo) on Ti-buffered Si substrates have been investigated. X-ray diffraction results reveal that the Nd2Fe14B-type phase in almost all the films is randomly oriented. Different thickness x (nm) for Co layers and y (nm) for FeCo layers were adopted in the multilayers. It is found that high remanence is achieved in the nanocomposite multilayer films consisting of the Nd2Fe14B-type phase and soft magnetic phase for Co with 6≥x≥4 and for FeCo with 10≥y≥6. The enhancement of the remanence in the nanocomposite multilayer films is attributed to the exchange coupling between the magnetically soft and hard phases. Increasing the soft magnetic components results in a continuously decreasing coercivity

Structure and magnetic properties of sputtered (Nd,Dy)(Fe,Co,Nb,B) \u3csub\u3e5.5\u3c/sub\u3e/M (M = FeCo,Co) multilayer magnets

The magnetic properties of nanocomposite multilayer magnets of the (Nd,Dy)(Fe,Co,Nb,B) 5.5/M (M = Co,FeCo) on Ti-buffered Si substrates have been investigated. X-ray diffraction results reveal that the Nd2Fe14B-type phase in almost all the films is randomly oriented. Different thickness x (nm) for Co layers and y (nm) for FeCo layers were adopted in the multilayers. It is found that high remanence is achieved in the nanocomposite multilayer films consisting of the Nd2Fe14B-type phase and soft magnetic phase for Co with 6≥x≥4 and for FeCo with 10≥y≥6. The enhancement of the remanence in the nanocomposite multilayer films is attributed to the exchange coupling between the magnetically soft and hard phases. Increasing the soft magnetic components results in a continuously decreasing coercivity

Identification of the bulk pairing symmetry in high-temperature superconductors: Evidence for an extended s-wave with eight line nodes

we identify the intrinsic bulk pairing symmetry for both electron and hole-doped cuprates from the existing bulk- and nearly bulk-sensitive experimental results such as magnetic penetration depth, Raman scattering, single-particle tunneling, Andreev reflection, nonlinear Meissner effect, neutron scattering, thermal conductivity, specific heat, and angle-resolved photoemission spectroscopy. These experiments consistently show that the dominant bulk pairing symmetry in hole-doped cuprates is of extended s-wave with eight line nodes, and of anisotropic s-wave in electron-doped cuprates. The proposed pairing symmetries do not contradict some surface- and phase-sensitive experiments which show a predominant d-wave pairing symmetry at the degraded surfaces. We also quantitatively explain the phase-sensitive experiments along the c-axis for both Bi_{2}Sr_{2}CaCu_{2}O_{8+y} and YBa_{2}Cu_{3}O_{7-y}.Comment: 11 pages, 9 figure

Quantifying atmospheric nitrogen deposition through a nationwide monitoring network across China

A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health

Structure and magnetic properties of N-containing Nd–Fe–B alloys prepared by mechanical alloying

The structure and magnetic properties of Nd2Fe14BNδ -based alloys prepared by mechanical alloying have been investigated. For the Nd14Fe78B8Ny series, a large amount of NdN, α-Fe, and a small Nd2Fe14B phase are observed in x-ray diffraction patterns. With increasing Nd content, the amount of the Nd2Fe14BNδ phase increases and α-Fe decreases gradually. When x≥25 in the NdxFe92-xB8Ny systems, some amount of the N-containing, Nd-rich phase appears. Meanwhile, the content of the nitrogen in the Nd2Fe14BNδ phase decreases and, correspondingly, the Curie temperature decreases. The coercivity and the maximum magnetic energy product of this series attain maxima at x = 25. A coercivity as high as 20 kOe has been achieved. The effect of nitrogen on the formation, composition, and magnetic properties of the Nd2Fe14BNδ compound is discussed

The effects of the thickness of magnetically hard- and soft-phase layers on magnetic properties and exchange coupling in multilayer magnets

The structure and magnetic properties of multilayer magnets containing a hard phase [HP≡ (Nd0.95Dy0.05)(Fe,Co,Nb,B) 5.5] and a soft phase (SP≡Fe and Fe65Co35) have been investigated. For the nanocomposite multilayer of Si(substrate)/Ti(30 nm)/[HP(x nm)/SP(y nm)] n/Ti(30 nm), the remanence enhancement has been observed at different thickness and volume fractions of hard- and soft-phase layers. The remanence increases and the coercivity decreases with the addition of soft phase, in comparison with the results of the single-layer film. For the multilayer of Si(substrate)/Ti(30 nm)/[HP(15 nm)/Fe(5 nm)] n/Ti(30 nm) annealed at 575 °C for 30 min, the coercivity of the multilayer reaches a maximum at n=20. Effects of the layer thickness and volume fraction of hard- and soft-phase layers on magnetic properties and exchange coupling in the multilayer films have been observed