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George Wolf - One of the best experts on this subject based on the ideXlab platform.

  • high pressure bulk synthesis of crystalline c6n9h3 hcl a novel c3n4 graphitic derivative
    Journal of the American Chemical Society, 2001
    Co-Authors: Zhihong Zhang, Kurt Leinenweber, Matt Bauer, Laurence A J Garvie, Paul F Mcmillan, George Wolf
    Abstract:

    A novel carbon Nitride Compound, structurally related to the proposed graphitic phase of C(3)N(4), has been synthesized in a bulk well-crystallized form. The new material, with stoichiometry C(6)N(9)H(4)Cl, was prepared through a solid-state reaction of 2,4,6-triamino-1,3,5-triazine with 2,4,6-trichloro-1,3,5-triazine at 1.0-1.5 GPa and 500-550 degrees C and also through a self-reaction of 2-amino-4,6-dichloro-1,3,5-triazine at similar conditions. X-ray and electron diffraction measurements on the yellowish Compound indicate a hexagonal space group (P6(3)/m) with cell parameters of a = 8.4379(10) A and c = 6.4296(2) A. This new Compound possesses a two-dimensional C(6)N(9)H(3) framework that is structurally related to the hypothetical P6m2 graphitic phase of C(3)N(4), but with an ordered arrangement of C(3)N(3) voids. The large voids in the graphene sheets are occupied by chloride ions with an equivalent number of nitrogen atoms on the framework protonated for charge balance. The composition of the sample was determined by bulk chemical analysis and confirmed by electron energy loss (EELS) spectroscopy. The chemical and structural model is consistent with bulk density measurements and with the infrared and (13)C NMR spectra. This work represents the first bulk synthesis of a well-characterized and highly crystalline material containing a continuous network of alternating carbon and nitrogen atoms.

  • high pressure bulk synthesis of crystalline c 6 n 9 h 3 hcl a novel c 3 n 4 graphitic derivative
    Journal of the American Chemical Society, 2001
    Co-Authors: Zhihong Zhang, Kurt Leinenweber, Matt Bauer, Laurence A J Garvie, Paul F Mcmillan, George Wolf
    Abstract:

    A novel carbon Nitride Compound, structurally related to the proposed graphitic phase of C(3)N(4), has been synthesized in a bulk well-crystallized form. The new material, with stoichiometry C(6)N(9)H(4)Cl, was prepared through a solid-state reaction of 2,4,6-triamino-1,3,5-triazine with 2,4,6-trichloro-1,3,5-triazine at 1.0-1.5 GPa and 500-550 degrees C and also through a self-reaction of 2-amino-4,6-dichloro-1,3,5-triazine at similar conditions. X-ray and electron diffraction measurements on the yellowish Compound indicate a hexagonal space group (P6(3)/m) with cell parameters of a = 8.4379(10) A and c = 6.4296(2) A. This new Compound possesses a two-dimensional C(6)N(9)H(3) framework that is structurally related to the hypothetical P6m2 graphitic phase of C(3)N(4), but with an ordered arrangement of C(3)N(3) voids. The large voids in the graphene sheets are occupied by chloride ions with an equivalent number of nitrogen atoms on the framework protonated for charge balance. The composition of the sample was determined by bulk chemical analysis and confirmed by electron energy loss (EELS) spectroscopy. The chemical and structural model is consistent with bulk density measurements and with the infrared and (13)C NMR spectra. This work represents the first bulk synthesis of a well-characterized and highly crystalline material containing a continuous network of alternating carbon and nitrogen atoms.

T Bell - One of the best experts on this subject based on the ideXlab platform.

  • corrosion properties of plasma Nitrided aisi 410 martensitic stainless steel in 3 5 nacl and 1 hcl aqueous solutions
    Corrosion Science, 2006
    Co-Authors: C X Li, T Bell
    Abstract:

    Abstract Samples of an AISI 410 martensitic stainless steel were plasma Nitrided at a temperature of 420 °C, 460 °C or 500 °C for 20 h. The composition, microstructure and hardness of the Nitrided samples were characterised using a variety of analytical techniques. In particular, the corrosion properties of the untreated and plasma Nitrided samples were evaluated using anodic polarisation tests in 3.5% NaCl solution and immersion tests in 1% HCl acidic water solution. The results showed that plasma nitriding produced a relatively thick Nitrided case consisting of a Compound layer and a nitrogen diffusion layer on the 410 stainless steel surface. Plasma nitriding not only increased the surface hardness but also improved the corrosion resistance of the martensitic stainless steel. In the immersion test, Nitrided samples showed lower weight loss and lower corrosion rate than untreated one. In the electrochemical corrosion tests, the Nitrided samples showed higher corrosion potentials, higher pitting potentials and greatly reduced current densities. The improved corrosion resistance was believed to be related to the iron Nitride Compound layer formed on the martensitic stainless steel surface during plasma nitriding, which protected the underlying metal from corrosive attack under the testing conditions.

Zhihong Zhang - One of the best experts on this subject based on the ideXlab platform.

  • high pressure bulk synthesis of crystalline c6n9h3 hcl a novel c3n4 graphitic derivative
    Journal of the American Chemical Society, 2001
    Co-Authors: Zhihong Zhang, Kurt Leinenweber, Matt Bauer, Laurence A J Garvie, Paul F Mcmillan, George Wolf
    Abstract:

    A novel carbon Nitride Compound, structurally related to the proposed graphitic phase of C(3)N(4), has been synthesized in a bulk well-crystallized form. The new material, with stoichiometry C(6)N(9)H(4)Cl, was prepared through a solid-state reaction of 2,4,6-triamino-1,3,5-triazine with 2,4,6-trichloro-1,3,5-triazine at 1.0-1.5 GPa and 500-550 degrees C and also through a self-reaction of 2-amino-4,6-dichloro-1,3,5-triazine at similar conditions. X-ray and electron diffraction measurements on the yellowish Compound indicate a hexagonal space group (P6(3)/m) with cell parameters of a = 8.4379(10) A and c = 6.4296(2) A. This new Compound possesses a two-dimensional C(6)N(9)H(3) framework that is structurally related to the hypothetical P6m2 graphitic phase of C(3)N(4), but with an ordered arrangement of C(3)N(3) voids. The large voids in the graphene sheets are occupied by chloride ions with an equivalent number of nitrogen atoms on the framework protonated for charge balance. The composition of the sample was determined by bulk chemical analysis and confirmed by electron energy loss (EELS) spectroscopy. The chemical and structural model is consistent with bulk density measurements and with the infrared and (13)C NMR spectra. This work represents the first bulk synthesis of a well-characterized and highly crystalline material containing a continuous network of alternating carbon and nitrogen atoms.

  • high pressure bulk synthesis of crystalline c 6 n 9 h 3 hcl a novel c 3 n 4 graphitic derivative
    Journal of the American Chemical Society, 2001
    Co-Authors: Zhihong Zhang, Kurt Leinenweber, Matt Bauer, Laurence A J Garvie, Paul F Mcmillan, George Wolf
    Abstract:

    A novel carbon Nitride Compound, structurally related to the proposed graphitic phase of C(3)N(4), has been synthesized in a bulk well-crystallized form. The new material, with stoichiometry C(6)N(9)H(4)Cl, was prepared through a solid-state reaction of 2,4,6-triamino-1,3,5-triazine with 2,4,6-trichloro-1,3,5-triazine at 1.0-1.5 GPa and 500-550 degrees C and also through a self-reaction of 2-amino-4,6-dichloro-1,3,5-triazine at similar conditions. X-ray and electron diffraction measurements on the yellowish Compound indicate a hexagonal space group (P6(3)/m) with cell parameters of a = 8.4379(10) A and c = 6.4296(2) A. This new Compound possesses a two-dimensional C(6)N(9)H(3) framework that is structurally related to the hypothetical P6m2 graphitic phase of C(3)N(4), but with an ordered arrangement of C(3)N(3) voids. The large voids in the graphene sheets are occupied by chloride ions with an equivalent number of nitrogen atoms on the framework protonated for charge balance. The composition of the sample was determined by bulk chemical analysis and confirmed by electron energy loss (EELS) spectroscopy. The chemical and structural model is consistent with bulk density measurements and with the infrared and (13)C NMR spectra. This work represents the first bulk synthesis of a well-characterized and highly crystalline material containing a continuous network of alternating carbon and nitrogen atoms.

C X Li - One of the best experts on this subject based on the ideXlab platform.

  • corrosion properties of plasma Nitrided aisi 410 martensitic stainless steel in 3 5 nacl and 1 hcl aqueous solutions
    Corrosion Science, 2006
    Co-Authors: C X Li, T Bell
    Abstract:

    Abstract Samples of an AISI 410 martensitic stainless steel were plasma Nitrided at a temperature of 420 °C, 460 °C or 500 °C for 20 h. The composition, microstructure and hardness of the Nitrided samples were characterised using a variety of analytical techniques. In particular, the corrosion properties of the untreated and plasma Nitrided samples were evaluated using anodic polarisation tests in 3.5% NaCl solution and immersion tests in 1% HCl acidic water solution. The results showed that plasma nitriding produced a relatively thick Nitrided case consisting of a Compound layer and a nitrogen diffusion layer on the 410 stainless steel surface. Plasma nitriding not only increased the surface hardness but also improved the corrosion resistance of the martensitic stainless steel. In the immersion test, Nitrided samples showed lower weight loss and lower corrosion rate than untreated one. In the electrochemical corrosion tests, the Nitrided samples showed higher corrosion potentials, higher pitting potentials and greatly reduced current densities. The improved corrosion resistance was believed to be related to the iron Nitride Compound layer formed on the martensitic stainless steel surface during plasma nitriding, which protected the underlying metal from corrosive attack under the testing conditions.

Marius Grundmann - One of the best experts on this subject based on the ideXlab platform.

  • band structure pseudopotential calculation of zinc blende and wurtzite aln gan and inn
    Physical Review B, 2003
    Co-Authors: Daniel Fritsch, Heidemarie Schmidt, Marius Grundmann
    Abstract:

    The electronic properties of the zinc-blende and wurtzite group-III Nitride Compound semiconductors AlN, GaN, and InN are studied within the empirical pseudopotential approach. Using ionic model potentials and the static dielectric screening function derived by Levine and Louie [Z.H. Levine and St.G. Louie, Phys. Rev. B 25, 6310 (1982)], the cationic and anionic model potential parameters were obtained from zinc-blende AlN, GaN, and InN experimental data. Exploiting the concept of transferable model potentials, we calculated the band structure of group-III Nitrides in zinc-blende and wurtzite phase using the same ionic model potential parameters. Within this step we had to include the anisotropy of wurtzite crystals into the screening function. From the empirical fits for the effective masses at the $\ensuremath{\Gamma}$ point, also a complete set of Luttinger and Luttinger-like $\mathbf{k}\ensuremath{\cdot}\mathbf{p}$ parameters has been extracted for zinc-blende and wurtzite Nitrides, respectively.