Electron Spin Resonance with g_eff 4.2 in YBa₂Cu₃O_6.35.
Model of Chain CopperOxygen Fragments

M. V. Eremin^1, *, R. M. Eremina², M. R. Gafurov¹, V. A. Ivan’shin^{1, 3}, I. N. Kurkin¹,
S. P. Kurzin¹, H. Keller⁴, and M. Gutmann⁵

¹Kazan State University, Kazan, 420008 Russia

²Kazan Physicotechnical Institute, Kazan, 420029 Russia

³Experimentalphysik V, EKM, Institut für Physik, Universitat Augsburg, D-86159 Augsburg, Germany

⁴Physik-Institut der Universitat Zürich, CH-8057 Zürich, Switzerland

⁵Laboratory for Neutron Scattering, ETH Zürich & Paul Scherrer Institut, CH-5232 Villigen, Switzerland

* e-mail: Mikhail.Eremin@ksu.ru

Received May 11, 1999

Abstract—Systematic measurements are made of ESR spectra with g 4.2 in YBa₂Cu₃O_6+y compounds with
various doping indices y. Temperature dependences of the spectrum intensity show that the ground states of the
centers are singlet and the energies of the excited states M_S = 1 correspond to 8–11 K. In general, the intensity
of the ESR spectra varies with time and depends on the sample preparation technology. The most probable mod-
els for the paramagnetic centers studied are considered to be chain fragments of copper ions of variable valence.
General laws governing the energy structure of these centers are described. © 2000 MAIK “Nauka/Interperi-
odica”.

Pleiades Publishing home page | journal home page | top

If you have any problems with this server, contact webmaster.