We report a La-139 NMR investigation of low-doped insulating manganite samples (LaMnO3+delta and La1-yCayMnO3+delta) as a function of temperature. A volume fraction with fast nuclear relaxations was revealed by the inhomogeneous loss of the NMR signal over a broad temperature interval. Comparison with muon spin rotation data demonstrates that the wipeout of the La-139 signal is mainly due to slowly fluctuating electric field gradients. This provides strong evidence for the slow diffusion,of lattice excitations, identified with Jahn-Teller small polarons.
Ultraslow polaron dynamics in low-doped manganites from 139La NMR-NQR and muon spin rotation / Allodi, Giuseppe; CESTELLI GUIDI, M.; DE RENZI, Roberto; Caneiro, A.; Pinsard, L.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 87:(2001), pp. 127206-1-127206-4. [10.1103/PhysRevLett.87.127206]
Ultraslow polaron dynamics in low-doped manganites from 139La NMR-NQR and muon spin rotation
ALLODI, Giuseppe;DE RENZI, Roberto;
2001-01-01
Abstract
We report a La-139 NMR investigation of low-doped insulating manganite samples (LaMnO3+delta and La1-yCayMnO3+delta) as a function of temperature. A volume fraction with fast nuclear relaxations was revealed by the inhomogeneous loss of the NMR signal over a broad temperature interval. Comparison with muon spin rotation data demonstrates that the wipeout of the La-139 signal is mainly due to slowly fluctuating electric field gradients. This provides strong evidence for the slow diffusion,of lattice excitations, identified with Jahn-Teller small polarons.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
