electronegativity/ spinel structuregeometryionic radiuselectronegativitytetrahedral cationsunit cell parameteroxide spinelssulphide spinelsoctahedral cationsSystematic trends in the geometry of 149 oxide and 80 sulfide binary and ternary spinels have been examined from the standpoint of ionic radius and ...
A unit cell of 3×3×3 of LaFe2O4 structure with grid k-point Brillouin zone having 111 atoms (O = 63, Fe = 40 and La = 8) was built for this study. Pseudo atomic calculations were performed on La (1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s2, 4p6, 4d10, 5s2, 5p6, 5 d...
摘要: A series of solid solutions of composition ZnxCo3-xO4 with 0 ≤x ≤ 1, crystallising in spinel structure have been characterised by measurements of unit cell parameter, electrical conductivity and magnetic susceptibility. The results have been rationalised on the basis of cation distribution...
and its structure is the inverted form of the spinel structure. It forms solid solutions with magnetite. Lattice disintegration structures form upon cooling. Ulvospinel is found in the form of irregularly shaped black grains and phenocrysts. The unit cell parameter a0(8.40-8.53 Á), the Curie...
Fig. 1. a) A perovskite-based metal oxide structure where the octahedral site can be observed and b) A Spinel-based metal oxide structure where both octahedral and tetrahedral sites can be observed. BO6 octahedra can be also found in spinel-based structures, which are cubic close-packed anio...
Phase relationship between ferrimagnetic semiconducting spinels of the type MCr2S4 and defect NiAs compositions of the type MCr2Se4 (where M=Mn, Fe, Co) are established. It was found that the amount of Se which can be substituted, with retention of the spinel structure, decreases from MnCr...
The structural change during cycles of LiMn2-xNdxO4(x=0.01) spinel was studied by X-ray powder diffraction which shows that the samples maintain spinel structure and after 100 cycles the symmetry of the unit cell increases. The charge-discharge curves of the obtained spinel show that after ...
To determine the ratio of tetrahedral voids to octahedral voids occupied in spinel and inverse spinel structures, we can follow these steps:1. Understand the Structures: - Normal Spinel Structure: In this st
Crystal structure The Fe2SiO4 spinel-type belongs to Fd-3m (227) space group symmetry and it crystallizes in an fcc (face-centered cubic) lattice. A unit cell of Fe2SiO4 is shown in Fig. 1. There are 56 atoms in the unit cell or eight unit formulas (8 Fe2SiO4). It contains 32 ...
The pressure dependence of the unit-cell volume of the S-FeVO, determined experimentally and via DFT calculations, is presented inFigure 5.Figure 5also includes the DFT results for the O-FeVO polymorph. According to DFT simulations, the unit-cell parameters of the orthorhombic structure at ambien...