Influence of Co-Content on the Optical and Structural Properties of TiOx Thin Films Prepared by Gas Impulse Magnetron Sputtering

Abstract

Nonstoichiometric (Ti,Co)Ox coatings were prepared using gas-impulse magnetron sputtering (GIMS). The properties of coatings with 3 at.%, 19 at.%, 44 at.%, and 60 at.% Co content were compared to those of TiOx and CoOx films. Structural studies with the aid of GIXRD indicated the amorphous nature of (Ti,Co)Ox. The fine-columnar, homogeneous microstructure was observed on SEM images, where cracks were identified only for films with a high Co content. On the basis of XPS measurements, TiO2, CoO, and Co3O4 forms were found on their surface. Optical studies showed that these films were semi-transparent (T > 46%), and that the amount of cobalt in the film had a significant impact on the decrease in the transparency level. A shift in the absorption edge position (from 337 to 387 nm) and a decrease in their optical bandgap energy (from 3.02 eV to more than 2.60 eV) were observed. The hardness of the prepared films changed slightly (ca. 6.5 GPa), but only the CoOx film showed a slightly lower hardness value than the rest of the coatings (4.8 GPa). The described studies allowed partial classification of non-stoichiometric (Ti,Co)Ox thin-film materials according to their functionality.

Surface and Electrical Characterization of Non-Stoichiometric Semiconducting Thin-Film Coatings Based on Ti-Co Mixed Oxides Obtained by Gas Impulse Magnetron Sputtering

“…The grain size increased with the higher cobalt content from 35 nm to 61 nm, except for the film containing 44 at.% of Co, which exhibited a larger grain size of 102 nm. These AFM measurements corroborate the results obtained by scanning electron microscopy, as previously reported in our publication [46]. It is evident that with an increase in the Co content, the maximum height of the surface profile decreased significantly, ranging from 22.94 to 5.05 nm.…”

“…Targets with Ti-Co compositions of 2 at.%, 1 50 at.% Co were used in the preparation. Targets were prepared using spark p tering (SPS) with a system provided by FCT GmbH (Rauenstein, Germany) [5 sintering, Co and Ti nanopowders (99.95%, Kurt Lesker, Dresden, Germany Lukasiewicz Research Network-Institute of Non-Ferrous Metals [46,57] were A detailed description of the Ti-Co target preparation method can be found in publication [48]. Multimagnetron configuration allowed for the deposition o films with varying Co content (3 at.%, 19 at.%, 44 at.%, and 60 at.%).…”

“…Targets were prepared using spark plasma sintering (SPS) with a system provided by FCT GmbH (Rauenstein, Germany) [55][56][57]. For sintering, Co and Ti nanopowders (99.95%, Kurt Lesker, Dresden, Germany) from the Lukasiewicz Research Network-Institute of Non-Ferrous Metals [46,57] were employed. A detailed description of the Ti-Co target preparation method can be found in a separate publication [48].…”

“…In many processes, such as the sol-gel and chemical vapor deposition (CVD), the amount of oxygen added to materials is maximized, which is associated with the significant challenge of deposition, where one must precisely control the so-called oxygen deficit. Techniques like Gas Impulse Magnetron Sputtering (GIMS) allow for the controlled introduction of oxygen during the process, thereby enabling the fabrication of non-stoichiometric materials [46,47]. The initiation of pulsed discharge in the interelectrode zone of the magnetron and the generation of vapor/plasma for coating synthesis are consequences of pulsatile gas dosing.…”

The Contribution of the Pore Size of Titanium DC (Direct Current) Sputtered Condensation Polymer Materials to Electromagnetic Interruption and Thermal Properties

“…This technology also has the advantage of conveniently coating various metals on samples, so it is applied in various ways to high-tech mechanical parts and semiconductors. There are studies on electrical properties, physical properties, thermal stability, biosignal sensors, and hydrophobic thin films using sputtering technology [13][14][15][16][17][18][19][20][21].…”