jiayannenu
第4楼2008/01/19
我有篇文献中有些关于Y114(YBaCo4O7)的XRD数据表,我还不十分懂,所说的原子位置等参数是指这些吗?我手中的样品的分子式与化学计量YBaCo4O7略有不同,O的含量稍大于7。如果行的话,帮我模拟看看是否是有序结构,谢谢老师的帮助!文献YBaCo4O7
jiayannenu
第6楼2008/01/19
如果附件加不上,请参照文献(可以从http://www.sciencedirect.com上搜索下载):
Martin Valldor, Magnus Andersson, The structure of the new compound YBaCo4O7 with a magnetic feature,Solid State Sciences 4 (2002) 923–931.
此文献中有Y114的XRD数据表。谢谢老师!文献中的表格我打在下面,有点乱,不知老师是否能懂!
Table 1
Structural parameters from the X-ray single crystal refinement (all thermal displacements in Å2)
Atom Wyckoff site x y z U11 U22 U33 U12 U13 U23
Y 2b 2/3 1/3 0.87335(8) 0.0079(6) 0.0079(6) 0.0073(8) 0.0040(3) 0.00000 0.00000
Ba 2b 2/3 1/3 1/2 0.0179(4) 0.0179(4) 0.0139(6) 0.0090(2) 0.00000 0.00000
Co1 2a 0 0 0.4402(4) 0.0117(5) 0.0117(5) 0.0149(6) 0.0059(2) 0.00000 0.00000
Co2 6c 0.17101(7) 0.82899(7) 0.6870(2) 0.0092(3) 0.0092(3) 0.0116(4) 0.0048(3) 0.0009(7) −0.0009(7)
O1 6c 0.496(1) 0.504(1) 0.7545(7) 0.032(3) 0.032(3) 0.072(3) 0.009(3) −0.023(2) 0.023(2)
O2 2a 0 0 0.2534(7) 0.008(3) 0.008(3) 0.012(3) 0.004(1) 0.00000 0.00000
O3 6c 0.1633(5) 0.8367(5) 0.5017(6) 0.069(4) 0.069(4) 0.011(2) 0.065(4) 0.001(1) −0.001(1)
R(obs) = 0.0274, Rw(obs) = 0.0275, R(all) = 0.0304, Rw(all) = 0.0275, formula weight: 574.00, space group: P63mc (No. 186), unit cell dimensions:
a = 6.2907, c = 10.2691 Å, cell volume: 351.93 Å3, Z: 2, density (calc.): 5.416 g cm−3.
Table 2
Results from Rietveld calculations on the neutron diffraction data. All sites are assumed to be fully occupied
Temperature (K) 100 10
Symmetry P63mc P63mc
a (Å) 6.2922(4) 6.2916(2)
c (Å) 10.2040(7) 10.2006(6)
Y (x,y, z)2b 2/3, 1/3, 0.875(1) 2/3, 1/3, 0.876(1)
Uiso (Å2) 0.004(1) 0.004(1)
Ba (x,y, z) 2b 2/3, 1/3, 0.5 2/3, 1/3, 0.5
Uiso (Å2) 0.021(2) 0.018(2)
Co1 (x,y, z) 2a 0, 0, 0.449(2) 0, 0, 0.451(2)
Uiso (Å2) 0.014(4) 0.003(4)
Co2 (x,y, z) 6c 0.161(1), 0.839(1) 0.158(1), 0.842(1),
0.694(2) 0.693(2)
Uiso (Å2) 0.005* 0.005*
O1 (x,y, z) 6c 0.498(1), 0.502(1), 0.498(1), 0.502(1),
0.757(2) 0.757(2)
Uiso (Å2) 0.037(1) 0.038(1)
O2 (x,y, z) 2a 0, 0, 0.257(2) 0, 0, 0.260(2)
Uiso (Å2) 0.005* 0.005*
O3 (x,y, z) 6c 0.1683(9), 0.1693(9),
0.8317(9), 0.499(1) 0.8308(9), 0.499(1)
Uiso (Å2) 0.032(1) 0.031(1)
wRP 0.0598 0.0638
RP 0.0468 0.0500
RF 0.1167 0.1265
χ2 7.586 8.61
No. of variables 29 29
No. of hkl in calc. 172 172
Excluded regions (deg) 0–22 0–22
再次感谢老师的帮助!