Structure and superconducting properties of YBa<SUB>2−x</SUB>Ln<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>7±δ</SUB> (Ln=La, Nd or Gd) and (Ln,Ln')<SUB>3−x</SUB>Ba<SUB>3+x</SUB>Cu<SUB>6</SUB>O<SUB>14+δ</SUB>
- Somasundaram, P.
- Nanjundaswamy, K. S.
- Umarji, A. M.
- Rao, C. N. R.
DOIAbstract
In YBa2−xLnxCu3O7±δ (Ln=La, Nd or Gd), the structure becomes tetragonal with increase in x and the TC of the orthorhombic phase decreases with x. Members of (Ln, Ln')3−xBa3+xCu6O14+δ (Ln=Nd or Gd) are generally tetragonal and non superconducting. Ln3Ba3Cu6O14+δ and LnBa2Cu3O7±δ (Ln=Nd or Gd) prepared by low-temperature decomposition of nitrates are also tetragonal and nonsuperconducting. Random occupation of Ba in LnBa2Cu3O7±δ or La3Ba3Cu6O14+δ appears to favour the tetragonal structure. Furthermore oxygen is less labile when La partly substituting Ba in these oxides
Add to ORKG