resumo
We report an unusual high-temperature ferromagnetic transition in bulk single-phase nanocrystalline La0.95Sr0.05MnO3+delta, achieved through localized strain and inhomogeneous Sr-doping. Magnetization measurements show a well defined transition at 290K and a broad one at similar to 150 K. HRTEM imaging reveals the strain on the highly crystalline nanometer sized grains and Sr-doping gradients, while oxygen homogeneity at the grain interfaces is confirmed by EELS-spectra. The magnetic behavior, far from the expected bulk phase diagram, shows how local doping and strain can strongly tune the macroscopic properties of a bulk material. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793657]
palavras-chave
GIANT MAGNETORESISTANCE; PHASE-TRANSITION; MANGANITES; LAMNO3; SIZE
categoria
Physics
autores
Das, S; Amaral, JS; De, K; Willinger, M; Goncalves, JN; Roy, A; Dhak, P; Giri, S; Majumder, S; Silva, CJR; Gomes, MJM; Mahapatra, PK; Amaral, VS
nossos autores
João Cunha de Sequeira Amaral
Investigador Auxiliar
João Nuno Santos Gonçalves
Investigador Júnior
Vitor Brás Sequeira Amaral
Professor CatedráticoProjectos
MULTIFOX: Nanometric Probing and Modification of Multiferroic Oxides (PTDC/FIS/105416/2008)
agradecimentos
The authors acknowledge the financial support from FCT through Grant No. SFRH/BPD/39262/2007 (S. Das), SFRH/BPD/63942/2009 (J. S. Amaral), UGC-Dr. D. S. Kothari Post-Doctoral Fellowship under the Project No. F.4-2/2006(BSR)/13-307/2008(BSR) (K. De) and from FCT through Grant Numbers SFRH/BPD/47128/2008 (K. De) and SFRH/BD/63698/2009 (A. Roy), and partial funding from the program COMPETE-FEDER under project PTDC/FIS/105416/2008.