Electron paramagnetic resonance (EPR) measurements on polycrystalline YBa2Cu3O7-δ prepared via the citrates and the usual ceramic route of firing the oxides and BaCO3 are reported. The single phase samples of orthorthombic YBa2Bu3O6.9 and tetragonal YBa2Cu3O6 obtained from a citrate precursor do not exhibit an EPR signal. However, a sample of the tetragonal and non-superconducting YBa2Cu3O6.15 prepared from a master sample of citrate-route synthesized YBa2Cu3O6.9 displays an EPR signal whose intensity peaks near 460 K in agreement with neutron diffraction data that show an antiferromagnetic transition in the 400 to 500 K temperature range. A probable explanation for these results is discussed.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering