Description of the publication:

Authors:

S. S. Kamble, A. Sikora, S. T. Pawar, N. N. Maldar, L. P. Deshmukh

Title:

Cobalt Sulfide Thin Films: Chemical Growth, Reaction Kinetics and Microstructural Analysis

Journal:

Journal of Alloys and Compounds

Year:

2015

Vol:

623

Pages:

466-472

ISSN/ISBN:

----

DOI:

http://dx.doi.org/10.1016/j.jallcom.2014.10.183

Link:

http://www.sciencedirect.com/science/article/pii/S0925838814026218

Keywords:

Chemical bath deposition, CoS, AFM, MFM, XRD, Optical studies

Abstract:

CoS thin films were successfully deposited from an aqueous alkaline bath containing ammonia and TEA as the complexing agents. Under the pre-optimized conditions (temperature = 80 ± 0.5 ºC, speed of the substrate rotation = 65 ± 2 rpm and deposition period = 90 min), ammonia and TEA quantities in the reaction bath were found to play a decisive role in the final product yield. Highly uniform, dark sea-green colored and tightly adherent deposits were obtained at our experimental conditions. As-obtained CoS thin films were polycrystalline in nature with hexagonal class of crystal system as derived from the X-ray diffraction analysis. Complex multifaceted webbed network of as-grown CoS crystals elongated and threaded into each other were observed through a scanning electron microscope. Atomic force micrographs revealed collapsing of the hillocks and filling of the valleys triggering decrease in the RMS roughness for increased TEA and NH3 quantities. Magnetic force microscopy (MFM) was employed to study surface topography in terms of magnetic mapping. MFM images highlighted the existence of the magnetic clusters imitating topography. Broad absorption edge with high absorption coefficient (α ≈ 104 cm-1) was observed for as-grown CoS thin films. Determined values of the optical bandgaps revealed influence of complexing environment on the final product.

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Example figure:

3D view of the surface of the sample combined with colour map representing magnetic domains orientation.

Used methods:

TapppingMode
Magnetic Force Microscopy