16 research outputs found
Superconductivity and electronic structure of the W7Re13B compound
The superconductor W7Re13B has been studied by the magnetic measurements and microwave absorption. The crystal structure of W7Re13B is cubic (¯-Mn type). This compound exhibits a sharp superconducting transition at a temperature of Tc = 7:2 K. The electronic structure of W7Re13B has been studied by X-ray photoelectron spectroscopy and the band structure has been calculated by the full-potential local-orbital minimum-basis method using the scalar-relativistic mode. The main contribution to the density of states at the Fermi level is from 5d electrons of W and Re. The W and Re bands are similar and substituting W by Re does not change the total density of states
Formation of MnBi by Mechanical Alloying
In this report we demonstrate that mechanical alloying is an alternative process to produce the intermetallic compound MnBi. Magnetically MnBi powder is prepared from the elemental powders by mechanical alloying in a planetary ball mill and then solid-state reaction at a relatively low temperature. The MnBi powder was aligned in a magnetic field and isostatic pressed. The X-ray pattern of powder reacted clearly shows the intensity peaks of the MnBi phase. After annealing the magnetization was about 1.0×10T m/kg
Electronic Structure of UCoB Compound
UCoB is a member of uranium intermetallic borides family which crystallizes in the hexagonal CeCoB structure. The experimental data suggest the occurrence of the spin-fluctuation behaviour of UCoB. In this paper we present the results of band structure calculations using the ab-initio tight binding linear muffin-tin orbital method. We found good agreement between the experimental X-ray photoemission spectroscopy valence band spectrum and the ab-initio results
Martensitic Transformations and Magnetic Properties of Ni-Mn-Sn Heusler Alloy Films
We report on structural and magnetic properties of (x=12÷14) films and compare them with those of the bulk Ni-Mn-Sn alloys. Magnetic measurements reveal clear presence of martensitic transformation in bulk alloys but in the flash-evaporated Ni-Mn-Sn thin films martensitic transformation is usually less visible. The best film samples annealed for 1 h at about 900 K exhibit clear signs of martensitic transformation: i.e., a small defect in magnetization and a substantial increase in ferromagnetic resonance line width
Magnetic Properties in Mn Pure Powder
The structural and magnetic properties of deformed powder of Mn obtained by mechanical grinding have been investigated using X-ray diffraction and magnetic measurements. The small values of ferromagnetic moment of Mn after grinding are attributed to the formation of a deformed phase at the surface of grains with enlargement of the interatomic spacings at the grains boundaries
Spin Reorientation and Exchange Coupling in the DyErFeSi Compounds
The structural and magnetic properties of DyErFeSi are investigated. X-ray analysis reveals that these compounds are of the tetragonal ThMn structure. In this structure the rare earth atoms occupy one crystallographic position 2(a). The unit cell contains 26 atoms. The spin reorientation temperature, T, was measured from the temperature dependence of the initial susceptibility using an ac bridge of mutual inductance of the Harsthorn type. Dy and Er have opposite contributions to the entire magnetic anisotropy. The spin reorientation temperature is found to be about 271 K in DyFeSi and 48 K in ErFeSi. The values are discussed applying the crystal field model. The value of the rare earth-transition metal exchange coupling constant J/k derived from the mean-field model analysis of the Curie temperature is about -13 K. The Fe-Fe exchange integral is much higher and is equal to about 75 K
Magnetics properties of TbNi4Al and DyNi4Al compounds: investigation via neutron diffraction and magnetometry
Electronic Structure and Transport Properties of UFe System
The electronic structure of the UFe compound was studied by X-ray photoemission spectroscopy and ab initio self-consistent tight binding muffin tin orbital method. This compound crystallizes in a cubic Laves phase. The calculated valence band spectrum is characterized by two peaks due to U(5f) and Fe(3d) states. We have found a good agreement between the experimental valence band spectrum and theoretical ab initio calculations. The carrier concentration estimated from the Hall effect amounts to ≈10 cm