Crystal structure and hyperfine interactions of delafossite (CuFeO₂) synthesized hydro­thermally

The powder specimen of CuFeO₂ delafossite was synthesized by a hydro­thermal method at 453 K. X-ray diffraction studies confirmed that the obtained pure delafossite phase was a mixture of the 3R and 2H polytypes, predominantly the former. Mössbauer spectral analysis revealed the paramagnetic state of the copper ferrite at room temperature. Below 12 K the spectra had com­pli­cated shapes of Zeeman sextets. Changes in the character of the hyperfine interactions did not correspond to the data reported for the single-crystal CuFeO₂. Magnetization measurements revealed that magnetic transition occurred at Néel temperature (T_N) = 12.5 K.