INVESTIGADORES
CANEIRO Alberto
artículos
Título:
Structural and magnetic study of PrBaCo2O5+d „d¶0.75… cobaltite
Autor/es:
C. FRONTERA; J.L. GARCÍA MUÑOZ; A E. CARRILLO; C. RITTER; D. MARTIN Y MARERO; A. CANEIRO
Revista:
PHYSICAL REVIEW B
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2004 vol. 70 p. 844281 - 844289
ISSN:
1098-0121
Resumen:
We have investigated the structural and magnetic properties of PrBaCo2O5+d sd.0.75d layered cobaltite. Bymeans of neutron and synchrotron x-ray powder diffraction we have determined the ordered distribution ofoxygen vacancies in PrOd planes. This order doubles both a and b lattice parameters from the perovskite cellparameter, forming a tetragonal (rather than orthorhombic) structure. On cooling, a paramagnetic to ferromagneticand an incomplete ferromagnetic to antiferromagnetic transition take place. This second transition leadsto a coexistence of ferromagnetic and antiferromagnetic order, forming a canted G-type antiferromagneticstructure. Magnetic data above the ferromagnetic transition evidence a large value of the effective paramagneticmoment of Co, implying that, well below room temperature, Co3+ ions in an octahedral environmentpresent a high-spin state, in contrast to RBaCo2O5.5 cobaltites.