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Synthesis of a new orthorhombic metastable form of CdS through solid-state reactions

1989-5
Bi̇lgi̇n, M.
Kızılyallı, Meral
Usanmaz, Ali
CdS has been prepared through solid-gas reactions of CdO with a sulfidizing gas mixture, at 750°C for 3 hr, and slow cooling under nitrogen atmosphere. The X-ray diffraction data of the product was indexed in a hexagonal system with unit cell parameters of a = 4.136 and c = 6.713Å, which agreed with the literature data. However, the presence of extra strong lines in the X-ray diffraction pattern and the splitting in the d-spacings showed that a new orthorhombic form of CdS was obtained. The unit cell dimensions were found to be a = 14.315, b = 14.074, and c = 14.568Å and the space group was found to be Pnnn. The IR absorption spectrum showed the formation of pure CdS. The X-ray powder pattern of this phase which was taken after 2 years showed only the presence of the hexagonal phase reported in the literature. This proved that the orthorhombic phase is metastable.