In oxygen-deficient 1-2-3 compound, 57Fe57Co) substituent on the chain, i.e. Cu(1) site, cannot sense the magnetic field as it is sandwiched between equal number of symmetrically disposed magnetic neighbors which are antiferromagnetically coupled along the sheets. Consequently, observation of a Zeeman split sextet, at room temperature, is widely regarded as a signature for the Cu(2) site. Our group and subsequently a couple of other groups have generated a large proportion of the magnetic species (designated as M) by thermal treatment of the 1-2-3 compound in an inert ambient at about 800°C. This species manifests itself as a doublet (M') after oxygen loading of the compound. It has been proposed that iron and cobalt substituents migrate from Cu(1) to Cu(2) site during the thermal treatment. In this communication, we present evidence to support our earlier contention that this species (M or M') is not situated in the Cu-O sheets, but occupies an interstitial site. The interstitial 57Fe(57Co) is not equidistant from the two neighboring Cu-O sheets, and senses a net magnetic field in the oxygen-deficient compound.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering