Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering Physics
Structure And Magnetism Of New Rare- Earth-Free Intermetallic Compounds: Fe3+Xco3−Xti2 (0 ≤ X ≤ 3), Balamurugan Balamurugan, Bhaskar Das, Manh Cuong Ngyuen, Xiaoshan Xu, Jie Zhang, Xiaozhe Zhang, Yaohua Liu, Ashfia Huq, Shah R. Valloppilly, Yunlong Jin, Cai-Zhuang Wang, Kai-Ming Ho, David J. Sellmyer
Structure And Magnetism Of New Rare- Earth-Free Intermetallic Compounds: Fe3+Xco3−Xti2 (0 ≤ X ≤ 3), Balamurugan Balamurugan, Bhaskar Das, Manh Cuong Ngyuen, Xiaoshan Xu, Jie Zhang, Xiaozhe Zhang, Yaohua Liu, Ashfia Huq, Shah R. Valloppilly, Yunlong Jin, Cai-Zhuang Wang, Kai-Ming Ho, David J. Sellmyer
Nebraska Center for Materials and Nanoscience: Faculty Publications
We report the fabrication of a set of new rare-earth-free magnetic compounds, which form the Fe3Co3Ti2-type hexagonal structure with P-6m2 symmetry. Neutron powder diffraction shows a significant Fe/Co anti-site mixing in the Fe3Co3Ti2 structure, which has a strong effect on the magnetocrystalline anisotropy as revealed by first-principle calculations. Increasing substitution of Fe atoms for Co in the Fe3Co3Ti2 lattice leads to the formation of Fe4Co2Ti2 , Fe5CoTi, and Fe6Ti2 with significantly improved …
Electron Diffraction Study Of Cobalt-Rich Hf-Co, Xingzhong Li, Yunlong Jin, Jeffrey E. Shield, Ralph Skomski, David J. Sellmyer
Electron Diffraction Study Of Cobalt-Rich Hf-Co, Xingzhong Li, Yunlong Jin, Jeffrey E. Shield, Ralph Skomski, David J. Sellmyer
Nebraska Center for Materials and Nanoscience: Faculty Publications
Intermetallic compounds having compositions from HfCo4 to HfCo8 were investigated by transmission electron microscopy, selected-area electron diffraction, and energy-dispersive x-ray spectroscopy. A major crystalline phase, closely related to the orthorhombic Zr2Co11 phase in structure, has been observed in the samples with the composition ranges from HfCo6 to HfCo8. The phase, referred to as either Hf2Co11 or HfCo7 phase in the literature, is actually one common phase, having a broad composition range and referred to as μ-phase in the present paper. In addition to the μ-phase, we …
Low-Temperature Fcc To L10 Phase Transformation In Copt(Bi) Nanoparticles, Frank M. Abel, Vasilis Tzitzios, David J. Sellmeyer, George C. Hadjipanayis
Low-Temperature Fcc To L10 Phase Transformation In Copt(Bi) Nanoparticles, Frank M. Abel, Vasilis Tzitzios, David J. Sellmeyer, George C. Hadjipanayis
Nebraska Center for Materials and Nanoscience: Faculty Publications
This work is focused on the effects of Bi substitution on the synthesis of CoPt nanoparticles with the L10 structure using a modified organometallic approach. The structural and magnetic properties of the nanoparticles have been studied and compared directly with those of CoPt nanoparticles synthesized by the same tech- nique but in the absence of Bi substitution. The as-synthesized particles at 330 ◦C have an average size of 11.7 nm and a partially ordered L10 phase with a coercivity of 1 kOe. The coercivity is increased to 9.3 kOe and 12.4 kOe after annealing for 1 hour at 600 …
Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, Pavel V. Lukashev, Liuyan Zhao, Tula R. Paudel, Theanne Schiros, Noah Hurley, Evgeny Y. Tsymbal, Aron Pinczuk, Abhay Pasupathy, Rui He
Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, Pavel V. Lukashev, Liuyan Zhao, Tula R. Paudel, Theanne Schiros, Noah Hurley, Evgeny Y. Tsymbal, Aron Pinczuk, Abhay Pasupathy, Rui He
Nebraska Center for Materials and Nanoscience: Faculty Publications
The effect of nitrogen doping on the phonon spectra of graphene is analyzed. In particular, we employ first-principles calculations and scanning Raman analysis to investigate the dependence of phonon frequencies in graphene on the concentration of nitrogen dopants. We demonstrate that the G phonon frequency shows oscillatory behavior as a function of nitrogen concentration. We analyze different mechanisms which could potentially be responsible for this behavior, such as Friedel charge oscillations around the localized nitrogen impurity atom, the bond length change between nitrogen impurity and its nearest neighbor carbon atoms, and the long-range interactions of the nitrogen point defects. We …