Raman and ultraviolet–visible spectroscopy of titanium chromium nitride thin films

Abstract

Titanium chromium nitride (TiCrN) films were prepared under various nitrogen flow rates (7-18 sccm) via co-sputtering. It was argued that the target poisoning effect governs the deposition process in nitrogen-rich atmospheres. The observed X-ray diffraction patterns suggested that the crystal structure of TiCrN coatings is a cubic close-packed (TiCr)N solid solution with (111) crystalline planes. The patterns also implied that the increased nitrogen content is accompanied by a tendency towards crystallite size enlargement. In addition to the main vibrational transitions, the micro-Raman spectroscopy detected the Raman third-order vibrational transition (2A + O) and a peak corresponding to one of the Raman second-order transitions (A + O). It was also revealed that the area under the peaks corresponding to chromium nitride first-order and second-order acoustic vibrational transitions increase with the increase in the nitrogen content of the samples. Ultraviolet-visible spectroscopy showed that the coatings can have a potential application in under-marine UV photodetector designs.

Surface Enhancement of Titanium-Based Coatings on Commercial Hard Steel Cutting Tools

“…The longitu optic (LO) and transverse optic (TO) bands, which are located in the optic region, corresponding central frequencies of 562 and 646 cm -1 , which are assigned for TiN TiAlN, respectively. The spectral characteristics, observed within the reported rang cording to previous TiN studies, can often be ascribed to the vibrational modes of tita and nitrogen ions in the acoustic and optic domains, respectively [33][34][35]. The det deviations in the peak positions of TiN and TiAlN suggest the presence of slight a tions in the levels of vacancies [36].…”

Effect of Ar/N2 flow ratio on the microstructure and mechanical properties of Ti-Cr-N coatings deposited by DC magnetron sputtering on AISI D2 tool steels

“…Furthermore, an increase in the intensity of the optical phonon band suggests the formation of metallic vacancies, while an increase in the intensity of the acoustical band indicates a nitrogen vacancy [38]. In comparison to the binary TiN and CrN, the Raman spectra of the Ti-Cr-N coating show the existence of a broad peak with low intensity corresponding to the second-order transitions (A + O) at the range of 740 to 795 cm − 1 , which is in good agreement with those reported by Mehr et al [18]. At 52 cm − 1 , all spectra present a very weak line that corresponds to the laser plasma line.…”

“…This indicates that Ar/N 2 flow ratio is expected to be a key factor, which affects not only the film's stoichiometry but also its structure and mechanical properties of the films. Few research groups have reported the effect of the main plasma parameters, such as the effect on the mechanical properties of the Ti-Cr-N films of the variation in discharge power [13,15,16] or the partial pressure of the N 2 flow [11,17,18]. However, to our knowledge, there is no study on the evolution of the properties of Ti-Cr-N thin film related to the Ar/N 2 flow ratio.…”