Effect of oxygen non-stoichiometry on the structural and magnetotransport properties of LaMn0.85Cr0.15O3+d

LILIANA B MORALES; R.D. ZYSLER; ALBERTO CANEIRO

JOURNAL OF SOLID STATE CHEMISTRY

Elsevier

Lugar: Amsterdam; Año: 2008 vol. 181 p. 1824 - 1832

0022-4596

Thermogravimetry, X-ray diffraction (XRD), d.c. magnetization, high-temperature susceptibility and electrical resistivity measurements were performed for LaMn0.85Cr0.15O3+d perovskites with accurate control of the oxygen content (0pdp0.11). For 0pdo0.09, three orthorhombic structures (Pnma) are found: for 0pdo0.045, the O0 phase (b/O2ocoa), for 0.045pdo0.06, the O00 (b/O2oaoc) and for 0.06pdo0.09, the O000 (aob/O2oc). For 0.09pdp0.11, a rhombohedral symmetry ðR3cÞ coexists with O000 in a biphasic field. Magnetic measurements revealed the ferromagnetic interactions (FM) character of the Mn3+?O?Cr3+ interaction, but also the intricate magnetic phase diagram due to the presence of multiple interactions (Mn3+,4+?O?Mn3+,4+, Cr3+?O?Mn3+, etc.). The comparison of the results for LaMn0.85Cr0.15O3+d with those of LaMn0.9Cr0.1O3+d allows discuss the role of Cr3+ on the structural, magnetic and magnetotransport properties of the LaMn1xCrxO3+d perovskites.