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91.
The magnetocaloric effect and thermal stability have been investigated on the new bulk metallic glass (BMG) Gd52.5Co16.5Al31 alloy. The extent of supercooled liquid region is 70 K, which is wider than that of any other Gd-Co-Al ternary BMGs. The magnetic entropy change (ΔSM) and relative cooling power (RCP) of 9.8 J/kg K and 9.1×102 J/kg are obtained, respectively, under a field change of 5 T. The large ΔSM and RCP values make Gd52.5Co16.5Al31 BMG attractive potential candidate for the magnetic refrigeration application. 相似文献
92.
We have investigated the influence of temperature and composition on cohesive and thermal properties of the doped manganites: Eu1−xYxMnO3 (0.0≤x≤1.0) by using a modified rigid ion model (MRIM). Theoretically, MRIM provides arguably the most realistic interaction potential to treat these properties. We have also computed the specific heat variations with temperatures for these manganites. The computed results obtained from MRIM have presented proper interpretation of the experimental data on Eu1−xYxMnO3. 相似文献
93.
94.
We have studied the high-pressure phase stability of LaF3 using full-potential linear augmented plane wave method. We have shown that experimentally observed orthorhombic phase is less stable compared to the theoretically predicted tetragonal structure above 25 GPa pressure. The structural transition is mainly due to the steric repulsion of ions and electrons to higher pressures. 相似文献
95.
T. Jeong 《Solid State Communications》2007,141(6):316-319
The electronic band structure of CeCoGe3 has been calculated using the self-consistent full potential nonorthogonal local orbital minimum basis scheme based on density functional theory. We investigated the electronic structure with the spin-orbit interaction and on-site Coulomb potential for the Ce-derived 4f orbitals to obtain the correct ground state of CeCoGe3. The exchange interaction between local f electrons and conduction electrons play an important role in their heavy fermion characters. The fully relativistic band structure scheme shows that spin-orbit coupling splits the 4f states into two manifolds, the 4f7/2 and the 4f5/2 multiplets. 相似文献
96.
The structure, magnetic property and magnetocaloric effect of GdCo2−xAlx (x=0, 0.06, 0.12, 0.18, 0.24, 0.4) compounds have been investigated by X-ray diffraction (XRD) and magnetic measurement techniques. The experimental results show that the GdCo2−xAlx (x≤0.4) compounds are single phase with a Laves-phase MgCu2-type structure. The Curie temperature Tc initially increases, and then decreases with increasing Al content. The maximum value of Tc, 418 K, is reached for the compound with x=0.06. The magnetic entropy change, which is determined from the temperature and field dependence of the magnetization by the Maxwell relation, decreases almost linearly with increasing Al content. 相似文献
97.
Deviations from the ideal quadrupole potential in a Paul ion trap create nonlinear resonances at certain operating points inside the stability diagram, where in the absence of potential pertubations storing times are very long. In the presence of those pertubations, however, the ions are lost from the trap. Since these resonances are mass dependent and the mass resolution is of the order of 100 it can be used to separate isotopes of a given element by choosing suitable trap operating conditions. Experiments on a natural mixture of Eu+ ions of mass 151 and 153 show that in a simple way, by proper choice of the operating point, the ions can be completely separated and laser-induced optical spectra of a single isotope can be received. This is the first time that mass separation in a Paul trap is performed by nonlinear effects in contrast to the usual way of using the mass dependent boundaries of the stability diagram 相似文献
98.
U. Krönert St. Becker Th. Hilberath H. -J. Kluge C. Schulz 《Applied Physics A: Materials Science & Processing》1987,44(4):339-345
Resonance ionization mass spectroscopy (RIMS) and pulsed-laser induced desorption (PLID) have been combined for ultrasensitive detection and spectroscopy of very small samples of refractive elements. The method has been tested and applied to laser spectroscopy of 5×109 atoms (1.5 pg) of195Au (T
1/2= 183d) implanted at the ISOLDE online mass separator with 60 keV into graphite. A pulsed thermal atomic beam was formed by laser desorption with a 10 ns NdYag laser pulse. Subsequently the atoms were photoionized in a three-colour, three-step resonant excitation to an autoionizing state. The selectivity was enhanced by a time-of-flight measurement of the photo ions. In resonance, one ion was detected per 105 atoms implanted resulting in a gain in detection efficiency by three orders of magnitude in comparison to the use of a continuous atomic beam. In the course of the experiments several unknown autoionizing states were found, and the lifetime of the 6d
2
D
3/2 state of gold was determined to be=10.7(6) ns. 相似文献
99.
K. Fuke F. Misaizu M. Sanekata K. Tsukamoto S. Iwata 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,26(Z1):180-182
Electronically excited states of magnesium-water cluster ions, Mg+(H2O)
n
,n=1–5, are studied by photodissociation after mass selection. The observed photodissociation spectra are assigned to the2P–2S type transitions localized on the Mg+ ion with the aid of ab initio CI calculations. In addition to evaporation of water molecules, photoinduced intracluster reaction to produce MgOH+(H2O)
n
is found to occur efficiently, with pronounced size dependence. The intriguing features observed in the mass spectrum of nascent cluster ions are discussed in relation to the stepwise solvation of this reaction. 相似文献
100.
Y. Lu Y. Morioka T. Matsui T. Tanaka H. Yoshii R. I. Hall K. Ito T. Hayaishi 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1995,35(2):125-129
The mass spectra of Xe
n
+
clusters (n=2–13) were recorded using a supersonic beam and an ion time-of-flight mass analyser. The yield of Xe
2
+
, Xe
3
+
and Xe
4
+
cluster ions was measured with a resolution of 0.1 Å (1 meV) in the 1024–1113 Å (11.1–12.1 eV) region. Autoionizing Rydberg series of Xe2 converging to theC
23/2u
state of Xe
2
+
were observed in the spectrum of Xe
2
+
. The photoionization yield of Xe
3
+
and Xe
4
+
ions each displayed similar broad features that contained no fine structure corresponding to vibrational states. The broad features were assigned to autoionizing Rydberg series by analogy with the dimer ion spectrum. 相似文献