α″-Fe16N2 single crystal films can be prepared successfully by facing targets sputtering directly onto NaCl(100) substrates in a mixture of argon and nitrogen gases. Both x-ray diffractometer and transmission electron microscope are employed to characterize the crystal structure of the films. The perfect electron diffraction patterns of α″-Fe16N2 single crystal in [1̄11], [011], and [001] directions can be distinctly observed by double tilting. These patterns confirm that the crystal structure of the films corresponds to a body-centered tetragonal (bct) lattice with the parameters of a=b=5.72 Å and c=6.29 Å . The x-ray diffraction patterns show that α″-Fe16N2 epitaxially grows on the NaCl(100) substrate with an orientation relationship α″-Fe16N2(001)∥NaCl(001) and α″-Fe16N2[100]∥NaCl[100]. The saturation magnetization of the Fe16N2 films is around 2100−2300 emu/cc, which agrees well with the value reported by Sugita et al..

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Articles you may be interested inEpitaxial high saturation magnetization FeN thin films on Fe(001) seeded GaAs(001) single crystal wafer using facing target sputterings Fe-N gradient films were prepared with a facing targets sputtering system. During deposition, the nitrogen pressure increased linearly up to a value, which is called the "ultimate pressure." Composition profiles, microstructure, magnetic properties, and corrosion resistance of the films were investigated by various methods. The experimental results indicate that the Fe-N films possess some composition and structural gradients. The Fe concentration decreases from the substrate to the film surface from 100 to 66 at. %. The phases d'-FelsNZ, ?/-Fe,N, E-FeXN(2

I. Ogura (2002) Influence of particle size on densification and abnormal expansion of LTCC multilayer substrate, British denoted series S, and the remainder to fabricate samples denoted series L. T wo series of LT CC ( low temperature co red ceramic) F igure 1 shows a owchart for the fabrication process of multilayer substrates were fabricated using glass the LTCC multilayer samples. Glass powder was mixed powders with diVerent particle sizes. T he series with with commercial Al 2 O 3 to form a glass-ceramic system ner particle size always showed better densi cation containing 60 wt-% glass and 40 wt-% Al 2 O 3 . A slurry was properties. A bnormal ex pansion was found in the formed by mixing the glass-ceramic powder with binder experimental samples as a result of the emergence and (P VB), solvent (toluene), and plasticiser (D BP ). The slurry growth of a second crystalline phase, Al 3Siwas ground in a ball mill and spread onto polyphenylene BCT /502 sulphide lm using the doctor blade casting method, to form green sheets 70-250 mm thick.

Fe–N gradient films and epitaxial Fe16N2 single-crystal films were prepared with a facing-target sputtering system. The Rutherford backscattering spectrum, x-ray diffraction, and selected area electron diffraction indicate that the gradient films possess some composition and structure gradient. The α′′-Fe16N2, γ-Fe4N, ε-FexN(2<x⩽3), and ζ−Fe2N phases are present in the gradient films at different depths. The α′′-Fe16N2 single-crystal films correspond to a deformed body-centered tetragonal structure with parameters of a=b=5.72 Å and c=6.29 Å. They grew epitaxially on a NaCl(100) substrate with an orientation relationship of α′′-Fe16N2(001)∥NaCl(001) and α′′-Fe16N2[100]∥NaCl[100]. Perfect electron diffraction patterns with perfect symmetry in the [1̄11], [011], and [001] directions can be observed distinctly by a rotational double tilting sample stand. By controlling N2 partial pressure, substrate temperature, and crystal orientation, α′′-Fe16N2 single-crystal films can be successfully grown epitaxially.

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conductivity 110-208 W m -1 K -1 (RT ); thermal expansion coeYcient 4•1Ö 10 -6 K -1 (from RT to around 400°C); T he processing of A g-20Pd thick lm metallisation volume resistivity 10 1 4 V cm; dielectric strength 15 kV conductors on A lN substrates has been investigated. mm -1 ; dielectric constant 8•7; bending strength 300 MPa. T he conductor lms performed almost as well on theSurface roughness R a was 0•405 mm. A lN substrate as on an Al 2 O 3 substrate. During sinter-A thick lm paste was prepared from the conductor ing, the glass f rit melts and ows towards the substrate, powders, additive agent powders, and organic vehicles. The while the A g-Pd powder sinters to form a porous chemical composition of the conductor was 80 wt-%Agstructure. A s a result an intricate physical bond forms 20 wt-%Pd. Most of the particles were 0•5 mm in diameter. between the A g-Pd conductor layer and the glass, andThe additive agent was a lead oxide glass frit. Table 1 lists the glass wets and bonds rmly to the A lN substrate.the major components and the physical properties of the In order to achieve this microstructure at the conductor/ glass powders. The composition of the glass frit was adjusted substrate interface, it is necessary for the glass to have so that its softening point changed over the range 300an optimum softening point ( 500-600°C) and to wet 700°C. The organic and inorganic constituents were blended the metal and the A lN substrate.BCT /526 at given ratios in order to provide a suitable rheology for screen printing. The rheology of the paste was maintained T he authors are in the Department of Materials at 10 Pa s. Science and Engineering, T singhua University,Screen printing was carried out on a printing machine,