ISSN:
0377-0486
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The Raman spectra of single crystals (grown by chemical vapour transport with I2, AlCl3, CrCl3 and InCl3 as transporting agents) and polycrystalline samples of spinel type MCr2S4 (M = Mn, Fe, Co, Zn, Cd), MIn2S4 (M = Mn, Fe, Co, Ni), MnCr2-2xIn2xS4 and Co1-xCdxCr2S4 were recorded. The main results obtained are (i) large resonance enhancement effects, (ii) breakdown of the translation symmetry in inverse spine (MIn2S4), which results in band broadening and the observation of more bands than group theoretically allowed, e.g. a clustering mode (A1g) at about 250 cm-1, (iii) two-mode behaviour of the breathing modes of the tetrahedral MS4 units (A1g) in both spinel solid solutions and partly inverse ternary spinels and (iv) frequency shifts of the observed bands caused by the tetrahedrally coordinated metal ions due to mass effects (F2g modes) and both bonding (ionic charge, covalency) and repulsion interactions (A1g modes).
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jrs.1250200207
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