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Full-Text Articles in Chemistry
Structural Evolution Of Ammonia Borane For Hydrogen Storage, Jinbo Yang, Jagat Lamsal, Qingsheng Cai, William B. Yelon, William Joseph James
Structural Evolution Of Ammonia Borane For Hydrogen Storage, Jinbo Yang, Jagat Lamsal, Qingsheng Cai, William B. Yelon, William Joseph James
Physics Faculty Research & Creative Works
We have studied the crystal structure of fully deuterated BH3NH3 using powder neutron diffraction at different temperatures. It is evident that an order-disorder phase transition occurs around 225 K. At low temperature, the compound crystallizes in the orthorhombic structure with space group Pnm21 and gradually transforms to a high temperature tetragonal structure with space group I4 mm above 225 K. At 16 K, the BD3-ND3 unit stacks along the c axis with a tilt angle of about 16° between the N-B bond and the c axis. As the temperature is increased, the BD3-ND3 groups start to reorient along the c …
A Magnetic And Mössbauer Spectral Study Of The Spin Reorientation In Ndfe₁₁Ti And Ndfe₁₁Th, Cristina Piquer, Fernande Grandjean, Olivier Isnard, Viorel Pop, Gary J. Long
A Magnetic And Mössbauer Spectral Study Of The Spin Reorientation In Ndfe₁₁Ti And Ndfe₁₁Th, Cristina Piquer, Fernande Grandjean, Olivier Isnard, Viorel Pop, Gary J. Long
Chemistry Faculty Research & Creative Works
The influence of hydrogenation on the spin reorientation in the presence of neodymium was investigated in NdFe11Ti and NdFe11TH. The magnetic properties of these compounds were determined by utilizing ac magnetic susceptibility, thermomagnetic, and iron-57 Mössbauer spectral analysis. It was found that the these compounds had two advantages as hard magnetic materials such as: a high iron content yielding high magnetization and a high Curie temperature. The investigation results show that these compounds undergo a spin-reorientation transition at ~185 K and at 100± K, from an axial magnetic phase at high temperature to a basal magnetic …
A New Layered Iron Fluorophosphates, Amitava Choudhury
A New Layered Iron Fluorophosphates, Amitava Choudhury
Chemistry Faculty Research & Creative Works
A new iron fluorophosphate of the composition, [C6N4H21] [Fe2F2(HPO4)3][H2PO4]·2H2O, I. has been prepared by the hydrothermal route. This compound contains iron fluorophosphate layers and the H2PO4- anions are present in the interlayer space along with the protonated amine and water molecules. The compound crystallizes in the monoclinic space group P21/c. (a = 13.4422(10) Å, b = 9.7320(10) Å, c = 18.3123(3) Å, ? = 92.1480°, V = 2393.92(5) Å3, Z = 4, …
Magnetic And Mössbauer Spectral Evidence For The Suppression Of The Magnetic Spin Reorientation In Tm₂Fe₁₇ By Deuterium, Fernande Grandjean, Olivier Isnard, Gary J. Long
Magnetic And Mössbauer Spectral Evidence For The Suppression Of The Magnetic Spin Reorientation In Tm₂Fe₁₇ By Deuterium, Fernande Grandjean, Olivier Isnard, Gary J. Long
Chemistry Faculty Research & Creative Works
The structural and magnetic properties of Tm2Fe17 and Tm2Fe17D3.2 are investigated by means of x-ray-diffraction, thermal, and ac magnetic susceptibility measurements, and iron-57 Mössbauer spectroscopy. Both compounds crystallize in a hexagonal P63/mmc space group with a Th2Ni17-like structure. Deuterium insertion into Tm2Fe17 induces large increases in the unit-cell volume, the saturation magnetization, and the ordering temperature. The unit-cell expansion is anisotropic, with a larger increase in the a lattice parameter than the c lattice parameter. A spin reorientation is observed at 90 K …
Structural, Magnetic, And Mössbauer Spectral Study Of Er₂Fe₁₇ And Its Hydrides, Fernande Grandjean, Olivier Isnard, Dimitri Hautot, Gary J. Long
Structural, Magnetic, And Mössbauer Spectral Study Of Er₂Fe₁₇ And Its Hydrides, Fernande Grandjean, Olivier Isnard, Dimitri Hautot, Gary J. Long
Chemistry Faculty Research & Creative Works
The structural and magnetic properties of the Er2Fe17Hx compounds, where x is 0, 1, 2, 3, and 3.8, have been investigated by means of powder x-ray diffraction, thermal and ac magnetic susceptibility measurements, and iron-57 Mössbauer spectroscopy. The Er2Fe17Hx compounds crystallize in the hexagonal P63/mmc space group with the Th2Ni17-like structure, a structure which has both an iron-rich stoichiometry and disorder of the erbium and iron-iron 4f-4f dumbbell sites. The increase in the lattice parameters, the magnetic ordering temperature, the saturation magnetization, and the …