info:eu-repo/semantics/article
The s - d exchange model as the underlying mechanism of magnetoresistance in ZnO doped with alkali metals
Fecha
2019-08Registro en:
Zapata, María Cecilia; Nieva, Gladys Leonor; Ferreyra, Jorge Mario; Villafuerte, Manuel Jose; Lanoel, Lucio; et al.; The s - d exchange model as the underlying mechanism of magnetoresistance in ZnO doped with alkali metals; IOP Publishing; Journal of Physics: Condensed Matter; 31; 34; 8-2019; 1-10
0953-8984
CONICET Digital
CONICET
Autor
Zapata, María Cecilia
Nieva, Gladys Leonor
Ferreyra, Jorge Mario
Villafuerte, Manuel Jose
Lanoel, Lucio
Bridoux, German
Resumen
High field magnetoresistance has been studied in epitaxial n-type ZnO:Na and ZnO:Li thin films in a temperature range between 4 K and 150 K. The resulting negative magnetoresistance can be well fitted using a semiempirical model of Khosla and Fischer based on third order contributions to the s-d exchange Hamiltonian. The parameters obtained from this model were carefully analyzed. One of these parameters is related to a ratio between electron mobilities at zero field (a non-exchange scattering mobility and an exchange or spin dependent one ). From Hall effect measurements was obtained, displaying a weak temperature dependence in accordance with highly n-doped ZnO while the extracted exhibits an anomalous T-dependence. On the other hand, our magnetoresistance data cannot be properly fitted using Kawabata´s expression based on a weak-localization model.