Characteristic features of the magnetic state of Cu-O chains in YBa2Cu3O6.0+x
Aleksashin B. A. , Bogdanovich A. M., Verkhovskii S. V. , Zhdanov Yu. I., Kozhevnikov V. L., Mikhalev K. N., Okulova K. A., Romanyukha A. A, Serikov V. V., Sorkin A. M., Tsurin V. A., Cheshnitskii A. I., Shvachko Yu. A., Anisimov V. I., Katsnel'son M. I., Likhtenshtein A. I., Trefilov A. V., Turzhevskii S. A.
The change in the state of Cu atoms in YBa2Cu306 0 + x (0.05<x<0.95) is studied on the basis of the measurements of the magnetic susceptibility, ESR, and NQR of 63Cu and the Mossbauer measurements of 57Fe. The results of calculations of the magnetic interaction, in combination with all other data collected, show that magnetic moments form at Cul atoms in the oxygen-deficient chains. At T~ 10 К the magnetic moments are "frozen-in" in the semiconducting region of the compositions (л<0.4). The behavior of the NQR frequencies near Tc is discussed.