Details

Autor(en) / Beteiligte

• Nguyen, L.H.
• Hung, L.X.
• Phuc, N.X.
• Nam, P.H.
• Ngan, L.T.T.
• Dang, N.V.
• Bau, L.V.
• Linh, P.H.
• Phong, P.T.

Titel

Composites (1 − x)La0.7Ca0.3MnO3/xLa0.7Sr0.2Ca0.1MnO3: Electrical transport properties and enhancing of low-field-magnetoresistance and colossal magnetoresistance

Ist Teil von

• Journal of alloys and compounds, 2020-12, Vol.849, p.156607, Article 156607

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Composites of (1 − x)La0.7Ca0.3MnO3/xLa0.7Sr0.2Ca0.1MnO3 were prepared via the sol–gel method combined with the energy milling method. The electrical transport and low-field magnetoresistance properties of the composites were systematically studied. As the La0.7Sr0.2Ca0.1MnO3 level increased, the metal-insulator transition temperature of the composites shifted to a higher temperature. The transport mechanisms in the insulating region of the composites were comprehensively analyzed via small polaron hopping (SPH) and variable range hopping (VRH) models. The combination of electron–electron interaction and spin wave scattering was considered to estimate the conduction mechanism in the metallic region of the composites. Both intrinsic magnetoresistance and extrinsic low-field magnetoresistance were enhanced from 30 K to the Curie temperature for the system. The results were explained on the basis of the competition between spin-dependent scattering and spin-polarized tunneling at La0.7Ca0.3MnO3 grain boundaries induced by interactions between La0.7Ca0.3MnO3 and La0.7Sr0.2Ca0.1MnO3 manganites. •Composites (1 − x)LCMO/xLSCMO were synthesized using a sol-gel method combined with the energy milling method.•XRD patterns and SEM showed that the composites consist of two chemically separated LCMO and LSCMO phases.•Both LFMR and CMR were enhanced over a wide temperature range.•The enhancing of LFMR and CMR originated from competition between spin-dependent scattering and spindependent tunneling.•The electrical transport is investigated using various models.