Effect of the magnetic impurity on the charge diffusion in highly dilute Ce doped LaMnO3

Autor(es)

Cabrera-Pasca, G. A. ^[1] ; Bosch-Santos, B. ^[2] ; Burimova, A. N. ^[2] ; Correa, E. L. ^[2] ; Carbonari, A. W. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Para, Fac Ciencias Exatas & Tecnol, BR-68440000 Abaetetuba, PA - Brazil

^[2] IPEN CNEN SP, Inst Pesquisas Energet & Nucl, BR-05508000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: AIP ADVANCES; v. 10, n. 1 JAN 1 2020.
• Citações Web of Science: 0

Resumo

LaMnO3+delta is a complex oxide, which, depending on the oxygen excess concentration, presents different crystalline structure and interesting magnetic and electric properties such as colossal magnetoresistance, polaron dynamics, multiferroic behavior, and charge-orbital ordering. This complexity requires different characterization techniques to draw a picture as complete as possible allowing a good understanding of these phenomena. Here, we have used the perturbed angular correlation (PAC) technique to measure hyperfine interactions at La and Mn sites of LaMnO3+delta(delta similar to 0.15) using Ce-140 and Cd-111 at La sites as probe nuclei in order to investigate within an atomic scale the magnetic and electric interactions in this compound. The results show that Cd-111 nuclei occupy highly symmetric local sites in agreement with a rhombohedral structure. The magnetic hyperfine field (B-hf) measured with Cd-111 at La sites is very small (B-hf = 0.40 T) due to the supertransferred magnetic field from Mn neighbors through oxygen orbitals. On the other hand, Ce-140 nuclei at La sites present a saturation field of around 3.7 T much higher than that expected for La sites (due to the weak transfer field by superexchange mechanism). In addition, for temperature range above the magnetic ordering (200-300 K) a dynamic hyperfine interaction was observed characterized by the attenuation parameter lambda(T) whose temperature dependence allowed to determine the activation energy (E-a) associated to charge transfer. The polarization of the 4f-electron of Ce impurities affects the local magnetic field at impurity sites as well as the E-a. (AU)

• Processo FAPESP: 19/15620-0 - Adequando nanoparticulas de MFe2O4 (M=Co,Ni) para aplicações biomédicas in vivo: dopagem com elementos de terras raras e recobimento biocompatível
• Beneficiário: Anastasia Nikolaevna Burimova
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/14001-1 - Projeto e construção de um espectrômetro digital: um equipamento mais eficiente e moderno para investigação de materiais utilizando técnica PAC
• Beneficiário: Rajendra Narain Saxena
• Modalidade de apoio: Auxílio à Pesquisa - Regular