Raman spectroscopy of (Fe,Li)-doped delafossite oxide CuCrO2

Mcconnellite, CuCrO2 and ellinaite, CaCr2O4, from varicoloured spurrite marble of the Daba-Siwaqa area, Hatrurim Complex, Jordan

“…In the Raman spectra of mcconnellite from Jordan, there is a strong band at 537–538 cm –1 , and a shoulder at 556–558 cm –1 (Fig. 4), which also appears in the Raman spectra of synthetic analogues (Aktas et al , 2012; Monteiro et al , 2017). Additionally, if the other strong bands at 458 cm –1 ( Eg ) and 709 cm –1 ( Ag1 ) are related to the Raman selection rule, then the band at 537–538 cm –1 (and the shoulder at 556–558 cm –1 ) breaks this rule and they are connected with structural defects (Majee and Bhobe, 2020; Han et al , 2020).…”

“…For the first time we provide the Raman spectra of mcconnellite (Fig. 4), which are similar to the spectra of synthetic CuCrO 2 , for which depending on orientation and/or composition modification significant changes of intensity of the main bands are observed (Aktas et al , 2012; Elkhouni et al , 2013; Monteiro et al , 2017, 2018; Han et al , 2020). In the Raman spectra of mcconnellite there are six main bands (Fig.…”

“…In the Raman spectra of mcconnellite there are six main bands (Fig. 4b, cm –1 ): 105, 210 ( Ag ), 458 ( Eg ), 538 ( P 1 ), 556 ( P 1 ′) and 709 ( A1g ) (Monteiro et al , 2018). The nature of the strong band at 538 cm –1 ( P 1 ) and the shoulder at 556 cm –1 ( P 1 ′) is currently disputable and is connected with structural defects of mcconnellite, which interferes with an action of the Raman selection rule (Majee and Bhobe, 2020; Han et al , 2020).…”

“…A phase similar to mcconnellite has been identified in a historical Cu–Pb-slag from Tsumeb, Namibia (Ettler et al , 2009). Recently, synthetic CuCrO 2 and other materials with a delafossite-type structure have been studied extensively because of their thermoelectric, optoelectric, electric, magnetic and superconductor properties (Kumar et al , 2012; Monteiro et al , 2017; Majee and Bhobe, 2020). Synthetic delafossite with the general formula Cu R 3+ O 2 is prepared at different temperatures by performing a solid-state reaction, usually at temperatures >850°C, by the sol-gel method, with a high-temperature post treatment (>650°C) or by hydrothermal synthesis at 180°C (Kim et al , 2020).…”

An all-sputtered photovoltaic ultraviolet photodetector based on co-doped CuCrO2 and Al-doped ZnO heterojunction

“…Figure 2 d illustrates the Raman scattering spectrum for AZO and co-doped CuCrO 2 materials. As we are aware, the delafossite structure (ABO 2 ) belongs to the R-3 m space group and can be irreducibly addressed by 57 : …”