Abstract
We report on high-temperature electron spin resonance studies of -site ordered YBaMnO and disordered YBaMnO. In the disordered sample we find that the linewidth is governed by spin-spin relaxation processes as in many other manganite systems. In contrast we find a Korringa-like spin relaxation with a slope of about 1 Oe/K above the charge-ordering transition and extending up to 930 K in the metal ordered YBaMnO samples. A Korringa law is a clear feature of a truly metallic state, pointing to an unconventional high-temperature phase of these ordered manganites. In agreement with the electron spin resonance (ESR) intensity this suggests that in the metallic high-temperature phase the ESR signal stems from Mn core spins which relax via the quasidelocalized electrons.
- Received 30 March 2012
DOI:https://doi.org/10.1103/PhysRevB.85.205121
©2012 American Physical Society