Magnets derived from inorganic materials (e.g., oxides, rare-earth–based, and intermetallic compounds) are key components of modern technological applications. Despite considerable success in a broad range of applications, these inorganic magnets suffer several drawbacks, including energetically expensive fabrication, limited availability of certain constituent elements, high density, and poor scope for chemical tunability. A promising design strategy for next-generation magnets relies on the versatile coordination chemistry of abundant metal ions and inexpensive organic ligands. Following this approach, we report the general, simple, and efficient synthesis of lightweight, molecule-based magnets by postsynthetic reduction of preassembled coordination networks that incorporate chromium metal ions and pyrazine building blocks. The resulting metal-organic ferrimagnets feature critical temperatures up to 242°C and a 7500-oersted room-temperature coercivity.

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Metal-organic magnets with large coercivity and ordering temperatures up to 242°C

Vibrational study of [(CH3)4N]2Cu0.5Zn0.5Cl4.

Ferroelectric properties of the [N(CH3)4]2CoCl2Br2 compound

The [N(CH3)4][N(C2H5)4]ZnCl4 compound has been synthesized by a solution-based chemical method. The X-ray diffraction study at room temperature revealed an orthorhombic system with P21212 space group. The complex impedance has been investigated in the temperature and frequency ranges 420–520 K and 200 Hz–5 MHz, respectively. The grain interior and grain boundary contribution to the electrical response in the material have been identified. Dielectric data were analyzed using the complex electrical modulus M * for the sample at various temperature. The modulus plots can be characterized by full width at half height or in terms of a non-exponential decay function ϕ(t) = exp[(−t/τ) β ]. The detailed conductivity study indicated that the electrical conduction in the material is a thermally activated process. The variation of the AC conductivity with frequency at different temperatures obeys the Almond and West universal law.

Electrical characterization of the [N(CH3)4][N(C2H5)4]ZnCl4 compound

Hydrogenated amorphous carbon nitride films that include presumably oxygen atoms were prepared by using the electron cyclotron resonance (ECR) plasma chemical vapor deposition (CVD) of mixed gases of He, BrCN, and H 2 O. By controlling the partial pressure of H 2 O, the relative number density of the hydrogen atoms was varied. The IR-band intensity analysis suggested that 7–22% of N atoms were incorporated into CN terminations bonding to the aromatic rings and that the NH y ( y  = 1 or 2) or OH terminations formed hydrogen bonds. The films were coated onto Al-doped ZnO (ZnO:Al) single crystal whiskers to manufacture cold cathode devices. The I – V characteristics of the devices were the Fowler–Nordheim type, and the work functions were determined to be 4.7 ± 0.4–1.9 ± 0.1 eV being dependent negatively on the partial pressure of H 2 O.

Hydrogenated amorphous carbon nitride with controlled hydrogen density — Structural analysis and electric field emission property

Raman and infrared spectra, conformational stability, barriers to internal rotation, vibrational assignment, and ab initio calculations of 3-methyl-3-butenenitrile

Andrea S. Drew

Papers

Raman and infrared spectra, conformational stability, barriers to internal rotation, vibrational assignment, and ab initio calculations of 3-methyl-3-butenenitrile