INVESTIGADORES
CANEIRO Alberto
artículos
Título:
Oxygen vacancies effect on phase separation in Pr0.5Ca0.2Sr0.3MnO3−δ
Autor/es:
D. NIEBIESKIKWIAT; A. CANEIRO; D.M. SANCHEZ
Revista:
JOURNAL OF APPLIED PHYSICS
Editorial:
AMER INST PHYSICS
Referencias:
Lugar: New York; Año: 2003 vol. 93 p. 8080 - 8082
ISSN:
0021-8979
Resumen:
We study the effect of the introduction of a controlled amount of oxygen vacancies on the magneticand transport properties of the phase separated manganite Pr0.5Ca0.2Sr0.3MnO32d , for d50 and0.01. This compound presents a paramagnetic to ferromagnetic ~FM! transition below TC;240 K,and then to a charge-ordered ~CO! and antiferromagnetic ~AFM! phase at TCO;175 K. However,below TCO an appreciable FM component (;20%) still survives, related to a FM volume immersedwithin the CO/AFM matrix. At low temperatures, in the mainly CO phase, the introduction ofoxygen vacancies enhances the FM ordering, with the consequent decrease of resistivity andmagnetoresistance ~MR!. On the contrary, in the FM phase ~in the range TCO,T,TC) themagnetization is reduced and the resistivity and MR increase. These results are discussed in theframe of percolative transport in metal–insulator mixtures, and frustrated double exchangeinteraction due to the interruption of some Mn–O–Mn chains.