Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical modulation of the electron work functionJiri. JanataCite this: Anal. Chem. 1991, 63, 22, 2546–2550Publication Date (Print):November 15, 1991Publication History Published online1 May 2002Published inissue 15 November 1991https://pubs.acs.org/doi/10.1021/ac00022a003ht…
A new stable compound in the Nd–Fe system has been identified as Nd5Fe17. The crystal structure belongs to the hexagonal space group P63/mcm, with a=2.0214(8) nm and c=1.2329(8) nm, and with 12 formula units per unit cell. This compound is a ferromagnet with Tc = 503 K and magnetization 162 emu/g at 4.2 K. Mössbauer s…
The effect of additives has been studied for the Sm2Fe17Nx compounds. Only Co addition increases the Curie temperature. The Ti, V, or Co additions increase the anisotropy field. The additions of these elements are favorable for the magnet fabrication. The magnet fabrication has been carried out by the Zn metal bonding…
The effects of nitrogen uptake on the structural and magnetic properties of RFe12−xTx alloys have been studied. Several interstitial nitrides with composition RFe12−xTxNy (R=Nd and Sm and T=Ti and V) were prepared by heat treating fine powders of RFe12−xTx alloys in N2 gas. Preliminary results show the following obser…
Indentation/crack length measurements were used to determine hardness and fracture toughness in twinned and detwinned single crystals of YBa2Cu3O6+δ (YBCO). Hardness was found to be isotropic and unaffected by twin boundaries or moisture; the average hardness value was 9.5 GPa. Fracture toughness (Kc) was determined t…
The charge distributions in chemically synthesized poly(2,2'-bithiophene) (PBT) complexes have been studied by x-ray photoelectron spectroscopy (XPS). XPS results suggest the presence of multiple chemical states for the ``dopants'' in perchlorate, iodide, and ${\mathrm{FeCl}}_{4}^{\mathrm{\ensuremath{-}}}$ complexes.…
A number of metal-bonded Sm2Fe17-N magnets have been fabricated. These magnets exhibit iHc = 5.1–17.0 kOe, Br = 6.4–8.4 kG, (BH)max=5.0–10.8 MGOe, Tc = 757 K, and ρ=6.2–6.7 g/cm3. Powder metallurgical techniques have been employed with a mixture of powdered Sm2Fe17-N and Zn, Sn, or In. Heat treatment is carried out in…
The effects of surface oxidation on the structural and magnetic properties of fine Fe particles prepared by the evaporation technique have been studied using transmission electron microscopy, x-ray photoelectron spectroscopy, superconducting quantum interference device magnetometry, and Mössbauer spectroscopy. By vary…
The relative importance of x-rays alone and of x-ray-generated primary and secondary electrons in damaging organic materials was explored by use of self-assembled monolayers (SAMs) on multilayer thin-film supports. The substrates were prepared by the deposit of thin films of silicon (0, 50, 100, and 200 angstroms) on…
The effects of hydrostatic pressure on the solid-phase epitaxial growth (SPEG) rate v of intrinsic Ge(100) and undoped and doped Si(100) into their respective self-implanted amorphous phases are reported. Samples were annealed in a high-temperature, high-pressure diamond anvil cell. Cryogenically loaded fluid Ar, used…
Efforts were made to obtain anisotropic thin-film magnets at low substrate temperature. This is an important criterion for practical applications such as to build motors. The influence of substrate materials as well as film thickness on the c-axis orientation were studied. It has been shown that thin-film magnets with…
Grain oriented 6.5% silicon steel with orientation (110)[001] was prepared by the secondary recrystallization technique for the first time. Magnetic properties of grain oriented 6.5% silicon steel have previously not been reported because of poor secondary recrystallization. In this paper, the magnetic properties of t…
We have previously shown that the corrosion behavior of ternary NdFeB magnets is affected by their oxygen, carbon, and nitrogen contents. The corrosion was measured in autoclaves which give accelerated testing environments of high heat and humidity. In this study, we relate this corrosion behavior in both NdFeB and Nd…
The hard magnetic properties of hot-worked R-Fe-B permanent magnets are improved by the addition of a minor amount of Cu (up to 2 at. %). Transmission electron microscope investigations show that the reason for the increase of the coercivity is the fact that Cu is mainly dissolved in the intergranular region separatin…
An interpretation of the low-temperature absorption spectra of AnF4 (An=U, Np, Pu) is presented. Using an effective operator Hamiltonian with orthogonalized free-ion operators and initializing crystal-field parameter values based on a superposition model calculation for An4+ sites with C2 symmetry, good agreement betw…
We succeed in inserting a number of nitrogen atoms into the RTiFe11 intermetallics. The nitrides retain the ThMn12-type structure, but with an increase in the unit cell volume. The crystallographic sites located by nitrogen atoms are determined by using neutron diffraction techniques. The nitrogen atoms are found to h…
With use of the self-consistent orthogonalized linear combination of atomic orbitals method in the local-density approximation, the electronic structures and the optical properties of eight different polycrystalline phases of ${\mathrm{SiO}}_{2}$ have been studied: They are \ensuremath{\alpha}-quartz, \ensuremath{\bet…
We propose what is to our knowledge the first use of a Pr(3+)-doped fluoride fiber amplifier as a practical amplifier operating at the 1.3-microm band, based on a demonstration of signal amplification and a spectroscopic investigation. The feasibility of the fluoride fiber amplifier is confirmed.
We have investigated the effects of reactant residence time on the properties of microwave-assisted chemical vapor deposited diamond films. Using a constant gas pressure of 40 Torr and gas composition of 1% CH4 in H2, the total gas flow rate was adjusted from 25 to 800 sccm which corresponds to apparent chamber reside…
The distribution of local stress in an atomic system can be calculated from its mechanical definition. While this leads, for a homogeneous system, to an expression equivalent to that derived from the virial theorem (thermodynamic definition), when local inhomogeneities are present the equivalence can be demonstrated o…