Antiferromagnetism in Li substituted YBa 2Cu 3O y studied by neutron powder diffraction measurements
Abstract
The magnetic structure of two well characterised YBa 2Cu 3-xLi xO y samples, with similar Li concentrations, x=0.08-0.09, and slightly different oxygen concentrations, y=6.06 and y=6.18, has been studied by neutron powder diffraction measurements. The lithium substitution is found to induce a strong decrease of the Néel temperature and of the mean ordered magnetic moment on the Cu2 sites. TN is ≈245 K for y=6.06 instead of 415-400 K in unsubstituted YBa 2Cu 3O y with y=6.0-6.2. The mean ordered moment at low temperature, μ0/ μB, is 0.33±0.03 for y=6.06, and 0.17±0.08 for y=6.18, instead of 0.64 in unsubstitued YBCO. These measured values are compared with other data from the literature and the various possible mechanisms of the strong lithium effect are discussed.
- Publication:
-
Physica C Superconductivity
- Pub Date:
- May 2001
- DOI:
- 10.1016/S0921-4534(00)01737-8
- Bibcode:
- 2001PhyC..353...93M