Fizika Tverdogo Tela, 1992 Volume 34, Issue 5,Pages 1482–1485(Mi ftt7495)
Low-temperature magnetic phase transition in $\mathrm{YBa}_{2}(\mathrm{Cu}_{1-x}\mathrm{Fe}_{x})_{3}\mathrm{O}_{7+\delta}(0.15\leqslant x \leqslant 0.30)$ accompanied by a change in the electronic-structure of $\mathrm{Fe}$ atoms