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.

Preparation of Copper Aluminium Oxide by Spray Pyrolysis

ABSTRACTCopper aluminium oxide(CuAlO2) particles, a promissing p-type TCO(transparent conducting oxide), were prepared by spray pyrolysis. Delafossite phase of CuAlO2 was obtained when copper nitrate, copper acetate and copper sulfate, divalent copper precursors, were used as copper precursor and aluminium nitrate as aluminium precursors. However, when copper chloride (CuCl, a monovalent copper precursor) was used, the delafossite phase was not obtained regardless of the type of aluminium precursor. The O2-doped CuAlO2 was obtained by using oxygen as carrier gas.