Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 7 of 7
Full-Text Articles in Physics
Mössbauer Study Of Permanent-Magnet Materials: Sm2Fe17-XAlX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer
Mössbauer Study Of Permanent-Magnet Materials: Sm2Fe17-XAlX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer
David Sellmyer Publications
The Fe57 Mössbauer spectra of Sm2Fe17-xAlx, where x=0, 1.0, 2.0, 3.0, and 4.0, have been measured at room temperature and analyzed. The ternary compounds Sm2Fe17-xAlx have the rhombohedral Th2Zn17 structure. Mössbauer measurements showed that all the compounds studied were ferromagnetic. The average hyperfine field was found to decrease with the increasing aluminum concentration, which is in qualitative agreement with magnetic measurements. The decrease in the average hyperfine field was from 224 kOe at x=0 to 174 kOe at x=4. By fitting the …
Sputtering Pressure Effects And Temperature-Dependent Magnetism Of Co/Pd Multilayers, S.Y. Jeong, Z.S. Shan, P. He, J.X. Shen, Y.B. Zhang, John A. Woollam, David J. Sellmyer
Sputtering Pressure Effects And Temperature-Dependent Magnetism Of Co/Pd Multilayers, S.Y. Jeong, Z.S. Shan, P. He, J.X. Shen, Y.B. Zhang, John A. Woollam, David J. Sellmyer
David Sellmyer Publications
The temperature dependence of the sputtering Ar pressure effects on magnetic properties and the coercivity mechanism of Co(2 Å)/Pd(13 Å) multilayers were studied as the sputtering Ar pressure varied from 3–15 mTorr and the temperature from 300 to 35 K. It is found that the roughness of the interfaces or film surface increases with increasing sputtering pressure, the anisotropy increases with decreasing temperature and increasing Ar pressure and shows a maximum at PAr≃12 mTorr, and the coercivity increases with Ar pressure and shows stronger temperature dependence at higher Ar pressure. The coercivity mechanism was analyzed in terms of …
Mössbauer, Magnetic, And Electronic-Structure Studies Of Yfe12-XMoX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer, H.H. Hamdeh
Mössbauer, Magnetic, And Electronic-Structure Studies Of Yfe12-XMoX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer, H.H. Hamdeh
David Sellmyer Publications
Mössbauer spectra, magnetization measurements, and self-consistent spin-polarized electronic structures of YFe12-xMox, where x=0.5, 1.0, 2.0, 3.0, and 4.0, are reported. The ternary compounds YFe12-xMox have the crystalline tetragonal ThMn12 structure. Analyses of the Mössbauer spectra show that Mo atoms occupy the 8i Fe sites of the ThMn12 structure, in agreement with previous observations. Room-temperature magnetic and Mössbauer measurements show that the compounds with x≤2.0 are ferromagnetic and with x≥3.0 are paramagnetic. Measurements at 25 K show that all the samples are magnetically ordered. The magnetic hyperfine field is …
Anisotropy And Magneto-Optical Properties Of Sputtered Co/Ni Multilayer Thin Films, Y.B. Zhang, John A. Woollam, Z.S. Shan, J.X. Shen, David J. Sellmyer
Anisotropy And Magneto-Optical Properties Of Sputtered Co/Ni Multilayer Thin Films, Y.B. Zhang, John A. Woollam, Z.S. Shan, J.X. Shen, David J. Sellmyer
David Sellmyer Publications
Several series of sputtered Co/Ni multilayer thin films have been investigated. The volume and interface contributions to the magnetic anisotropy were determined from magnetization measurements, and the interface anisotropy, Ki= 0.23 ± 0.03 erg/cm2, was found to support perpendicular magnetic anisotropy. The anisotropy constant, K, increased with the Au buffer layer thickness, indicating the buffer layer was crucial to the perpendicular magnetic anisotropy. The polar Kerr rotation and coercivity as a function of temperature, and room temperature magneto-optical figure of merit are presented in this paper.
Magnetic And Magneto-Optical Properties Of Mn5(Ge1-XMX)3 Alloys With M=Sn, Pb, Y. Zhang, A.P. Runge, Z.S. Shan, David J. Sellmyer
Magnetic And Magneto-Optical Properties Of Mn5(Ge1-XMX)3 Alloys With M=Sn, Pb, Y. Zhang, A.P. Runge, Z.S. Shan, David J. Sellmyer
David Sellmyer Publications
We report on the magnetic and magneto-optical properties of the intermetallic alloys Mn5(Ge1-xMx)3, where M=Sn, Pb. Generally, these alloys were ordered ferromagnetically at T≥300 K for x<0.3. The structure of Mn5(Ge1-xSnx)3 remains in the hexagonal Mn5Si3 (hP16) phase up to x=0.25 and then changes to Ni2In (hP6) as x approaches 1. The magnetization and Curie temperature of these alloys is largest for small x and reach a minimum value near x=0.5. The room temperature Polar Kerr rotation, however, …
Electronic Structure And Curie Temperature Of Yfe12-XMoXNY Compounds, A.S. Fernando, J.P. Woods, Sitaram Jaswal, D. Welipitiya, B.M. Patterson, David J. Sellmyer
Electronic Structure And Curie Temperature Of Yfe12-XMoXNY Compounds, A.S. Fernando, J.P. Woods, Sitaram Jaswal, D. Welipitiya, B.M. Patterson, David J. Sellmyer
David Sellmyer Publications
The electronic structures of YFe12-xMoxNy , where x=1.0, 2.0 and y=0, 0.7, have been studied with photoemission and spin-polarized calculations. The peak near the Fermi level in the energy distribution curves (EDC) becomes successively broader with larger Mo concentration. The features in the calculated density of state at 1.3 and 2.7 eV are not readily seen in the EDC, and this may be due to lifetime effects in these compounds. Finally, changes in Curie temperature (Tc) with the change of N or Mo concentration are compared with prediction of the …
Magnetic Properties Of Nd(Fe,Ti) 12 And Nd(Fe,Ti) 12NX Films Of Perpendicular Texture, D. Wang, David J. Sellmyer, I. Panagiotopoulos, D. Niarchos
Magnetic Properties Of Nd(Fe,Ti) 12 And Nd(Fe,Ti) 12NX Films Of Perpendicular Texture, D. Wang, David J. Sellmyer, I. Panagiotopoulos, D. Niarchos
David Sellmyer Publications
Nd(Fe,Ti)12 and Nd(Fe,Ti)12Nx films textured with c axis perpendicular to the film plane were synthesized by sputtering. For the Nd(Fe,Ti)12 films a spin reorientation took place at about 170 K. For the Nd(Fe,Ti)12Nx films, the anisotropy field is about 85 kOe at room temperature and 130 kOe at 5 K, corresponding to a coercivity of 2.7 and 12 kOe, respectively. Initial magnetization curves show a behavior characteristic of nucleation type of magnetization reversal mechanism. Attempts were made to fit the experimental data with Kronmüller's magnetization reversal model. The results suggest that nucleation …