81 research outputs found
SOFT MAGNETIC Fe-BASED METALLIC GLASSES PREPARED BY FLUXING AND WATER-QUENCHING
Abstract. [(Fe 0.5 Co 0.5 ) 0.75 B 0.20 Si 0.05 ] 96 Nb 4 soft magnetic bulk metallic glasses were prepared by fluxing and water-quenching in a silica tube. Dimension of the bulk metallic glass specimens was up to 7.7 mm in diameter, which is about 1.5 times larger than those prepared by Cu mold-casting. The critical cooling rate of [(Fe 0.5 Co 0.5 ) 0.75 B 0.20 Si 0.05 ] 96 Nb 4 alloys with fluxing for forming a metallic glass phase was 150 -170 K/s, which was considerably smaller than that without fluxing. Saturation magnetization was 1.13 T, and coercivity was lower than 20 A/m. Fluxing suppresses heterogeneous nucleation by isolating the nucleation sites from the molten alloys and improves their glass-forming ability
Large quantum nonlinear dynamic susceptibility of single-molecule magnets
The nonlinear dynamical response of Mn single-molecule magnets is
experimentally found to be very large, quite insensitive to the spin-lattice
coupling constant, and displaying peaks reversed with respect to classical
superparamagnets. It is shown that these features are caused by the strong
field dependence of the relaxation rate due to the detuning of energy levels
between which tunneling takes place. The nonlinear susceptibility technique,
previously overlooked, is thus proposed as a privileged probe to ascertain the
occurrence of quantum effects in mesoscopic magnetic systems.Comment: 4 pages, 4 figure
Pressure induced Superconductor-Insulator transition in the spinel compound CuRh2S4
We performed resistivity measurements in CuRhS under
quasi-hydrostatic pressure of up to 8.0 GPa, and found a pressure induced
superconductor-insulator (SI) transition. Initially, with increasing pressure,
the superconducting transition temperature increases from 4.7 K at
ambient pressure to 6.4 K at 4.0 GPa, but decreases at higher pressures. With
further compression, superconductivity in CuRhS disappears abruptly
at a critical pressure between 5.0 and 5.6 GPa, when it becomes an
insulator.Comment: 4 pages, 4 figure
Giant cell tumor of the temporal bone â a case report
BACKGROUND: Giant cell tumor is a benign but locally aggressive bone neoplasm which uncommonly involves the skull. The petrous portion of the temporal bone forms a rare location for this tumor. CASE PRESENTATION: The authors report a case of a large giant cell tumor involving the petrous and squamous portions of the temporal bone in a 26 year old male patient. He presented with right side severe hearing loss and facial paresis. Radical excision of the tumor was achieved but facial palsy could not be avoided. CONCLUSION: Radical excision of skull base giant cell tumor may be hazardous but if achieved is the optimal treatment and may be curative
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