Strong oxygen-isotope effect on the intrinsic resistivity in the ferromagnetic state of manganites

Guo-Meng Zhao , D. J Kang , Wilfrid Prellier (1) , M. Rajeswari , H. Keller , T. Venkatesan (2) , R. L Greene (3)

1 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
2 NUS - National University of Singapore
3 AUF - Agence Universitaire de la Francophonie

Oxygen-isotope effects on the intrinsic resistivity have been studied in high-quality epitaxial thin films of La 0.75 Ca 0.25 MnO 3 and Nd 0.7 Sr 0.3 MnO 3. We found that the residual resistivity o increases by about 15͑3͒% upon replacing 16 O by 18 O. Furthermore, the temperature dependent part of the resistivity at low temperatures consists of an AT 4.5 term contributed from two-magnon scattering, and a B s /sinh 2 (ប s /2k B T) term which arises from scattering by a soft optical phonon mode. The absolute magnitudes of the coefficient A and the phonon energy ប s for both isotope samples are in quantitative agreement with theoretical predictions.

Domaines: Physique [physics]; Chimie; Matériaux

Guo-Meng Zhao, D. J Kang, Wilfrid Prellier, M. Rajeswari, H. Keller, et al.. Strong oxygen-isotope effect on the intrinsic resistivity in the ferromagnetic state of manganites. Physical Review B, 2000, 63 (6), pp.060402. ⟨10.1103/PhysRevB.63.060402⟩. ⟨hal-03544313⟩