Orientation of the main axis of the electric field gradient at the iron nucleus in some iron doped copper oxide compounds

1990 ◽  
Vol 55 (1-4) ◽  
pp. 1261-1265 ◽  
Author(s):  
P. Dalmas De Réotier ◽  
P. Vulliet ◽  
A. Yaouanc ◽  
P. Chaudouët ◽  
J. P. Sénateur ◽  
...  
2011 ◽  
Vol 38 (10) ◽  
pp. 787-799 ◽  
Author(s):  
Werner Lottermoser ◽  
Günther J. Redhammer ◽  
Sven-Ulf Weber ◽  
Fred Jochen Litterst ◽  
Gerold Tippelt ◽  
...  

1976 ◽  
Vol 5 (11) ◽  
pp. 1257-1258 ◽  
Author(s):  
Izumi Motoyama ◽  
Noriko Shimojima ◽  
Sei-ichiro Iijima ◽  
Hirotoshi Sano

1977 ◽  
Vol 32 (7-8) ◽  
pp. 507-512 ◽  
Author(s):  
F. Parak ◽  
U. F. Thomanek ◽  
D. Bade ◽  
B. Wintergerst

Abstract The EFG-tensor at the position of the Fe-atom of CO-liganded sperm whale myoglobin has been investigated by nuclear γ-resonance absorption experiments on single crystals. In addition the tem­ perature dependence of the quadrupole splitting of the 14.4 keV level of the iron nucleus was measured. An unambiguous solution for the magnitude and the orientation of the field gradient tensor could only be obtained with the assumption that a C2-axis perpendicular to the haem plane is one principal axis of the electric field gradient tensor. Within this solution the electronic struc­ture of the iron is described by a singlet ground state with ηz = 0.75 and the largest EFG component perpendicular to the haem plane.


Author(s):  
Samuel Silva dos Santos ◽  
Michel L. Marcondes ◽  
Ivan P. Miranda ◽  
Pedro Rocha-Rodrigues ◽  
Lucy Vitória Credidio Assali ◽  
...  

An ab-initio study for several hybrid improper ferroelectric (HIF) materials in the Ruddlesden-Popper phases and double perovskites structures is here presented. The focus is on the correlation between the electric...


2007 ◽  
Vol 62 (12) ◽  
pp. 711-715 ◽  
Author(s):  
Ahmad Seif ◽  
Mahmoud Mirzaei ◽  
Mehran Aghaie ◽  
Asadollah Boshra

Density functional theory (DFT) calculations were performed to calculate the electric field gradient (EFG) tensors at the sites of aliminium (27Al) and nitrogen (14N) nuclei in an 1 nm of length (6,0) single-walled aliminium nitride nanotube (AlNNT) in three forms of the tubes, i. e. hydrogencapped, aliminium-terminated and nitrogen-terminated as representatives of zigzag AlNNTs. At first, each form was optimized at the level of the Becke3,Lee-Yang-Parr (B3LYP) method, 6-311G∗∗ basis set. After, the EFG tensors were calculated at the level of the B3LYP method, 6-311++G∗∗ and individual gauge for localized orbitals (IGLO-II and IGLO-III) types of basis sets in each of the three optimized forms and were converted to experimentally measurable nuclear quadrupole resonance (NQR) parameters, i. e. quadrupole coupling constant (qcc) and asymmetry parameter (ηQ). The evaluated NQR parameters revealed that the considered model of AlNNT can be divided into four equivalent layers with similar electrostatic properties.With the exception of Al-1, all of the three other Al layers have almost the same properties, however, N layers show significant differences in the magnitudes of the NQR parameters in the length of the nanotube. Furthermore, the evaluated NQR parameters of Al-1 in the Al-terminated form and N-1 in the N-terminated form revealed the different roles of Al (base agent) and of N (acid agent) in AlNNT. All the calculations were carried out using the GAUSSIAN 98 package program.


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