共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
C. Acha M. Monteverde M. Núñez-Regueiro A. Kuhn M. A. Alario Franco 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,32(4):421-428
The electronic and positronic properties of the pentanary semiconductor alloys GaxIn1-xPySbzAs1-y-z lattice matched to GaSb have been studied. The electron wave function is calculated semiempirically using the pseudopotential
band model under the virtual crystal approximation. The positron wave function is evaluated under the point core approximation
for the ionic potential. Electronic and positronic quantities namely, electronic structure and band gaps, positron band structure,
effective mass and affinity, and electron-positron momentum densities have been predicted and their dependence on the phosphorus
composition has been discussed.
Received 30 August 2002 / Received in final form 12 February 2003 Published online 24 April 2003 相似文献
17.
T. Chatterji K. Siemensmeyer S. Welzel W. Caliebe 《The European Physical Journal B - Condensed Matter and Complex Systems》2004,42(2):205-217
We have investigated the magnetic ordering of Nd2-x
Ce
x
CuO4 for x = 0, 0.09, 0.13, 0.15 and 0.18 by neutron diffraction at low temperatures down to 33 mK and under magnetic field up to 5 tesla applied along [1,-1,0] crystallographic direction. At zero applied magnetic field Cu magnetic sublattice orders at
, 210, 130 and 105 K for x = 0, 0.09, 0.13, 0.15, respectively. No long range magnetic order of the Cu could be detected for x = 0.18. The magnetic order of Nd was found in all samples, with a gradual increase of the polarized magnetic moment with decreasing temperature, saturating around 1 K. Hyperfine induced nuclear polarization of the Nd nuclear spin has been observed below about 400 mK for samples with x = 0, 0.13, 0.15 and 0.18. Field variation of the intensities of the principal and superstructure reflections of Nd2-x
Ce
x
CuO4 at millikelvin temperatures shows a field-induced second-order double-k to single-k phase transition at H
c
= 0.75 and 0.56 tesla for samples with x = 0 and 0.15, respectively at T = 50 mK. We have also investigated the polarization of the Nd electronic sublattice due to the field of the Cu sublattice by the element specific X-ray resonant magnetic scattering investigation with synchrotron radiation.Received: 9 April 2004, Published online: 14 December 2004PACS:
75.25. + z Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.)T. Chatterji: Has changed his surname from Chattopadhyay to Chatterji. 相似文献
18.
19.