Octahedral cation distribution in palygorskite

Jahn-Teller distortions, cation ordering and octahedral tilting in perovskites.

In transition metal oxides, preferential occupation of specific d orbitals on the transition metal ion can lead to the development of a long-range ordered pattern of occupied orbitals. This phenomenon, referred to as orbital ordering, is usually observed indirectly from the cooperative Jahn-Teller distortions (CJTDs) that result as a consequence of the orbital ordering. This paper examines the ...

Octahedral tilting in cation-ordered perovskites--a group-theoretical analysis.

Group-theoretical methods are used to enumerate the structures of ordered perovskites, in which 1:2 and 1:3 ordering of B and B' cations is considered in combination with the ubiquitous BX6 (or B'X6) octahedral tilting. The cation ordering on the B-cation site is described by irreducible representations of the Pm3 m space group of the cubic aristotype: Lambda1 (k = 1/3,1/3,1/3) for the cation o...

Genesis and distribution of palygorskite and associated clay minerals in rafsanjan soils on diferent geomorphic surfaces

Cation distribution in natural ferrites

Mossbauer spectra of jacobsite have been recorded at temperatures of 4.2, 125, 180, 240 and 300 K and with an external magnetic field of 60 kOe applied parallel to the incident radiation at 4.2 K. The results show the presence of two different magnetic hyperfine interactions associated with the iron nuclei. Spectra of samples in external magnetic fields indicate the same sign for the magnetic h...

Cation Distribution Tuning of Solution Combusted CoFe2O4 Powders

In this work, the different fuels (citric acid, glycine and urea) were used for solution combustion synthesis of CoFe2O4 powders. X-ray diffraction, Raman spectroscopy, electron microscopy and vibrating sample magnetometry techniques were employed for characterization of phase evolution, cation distribution, microstructure and magnetic properties of the as-combusted CoFe2O4 powders. Single phas...