Deoxygenation Enhanced Double-Resistivity-Peak Properties in Polycrystalline La0.7Ca0.3Mn0.92Cr0.08O3-δ
FANG Jun1, TIAN Jian-Jun1, WANG Fang1, SONG Wen-Hai2, HUANG Zhen1, CHEN Jing-Lin1
1High Magnetic Field Laboratory, Institute of Plasma Physics, Hefei 230031
2Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei 230031
Deoxygenation Enhanced Double-Resistivity-Peak Properties in Polycrystalline La0.7Ca0.3Mn0.92Cr0.08O3-δ
1High Magnetic Field Laboratory, Institute of Plasma Physics, Hefei 230031
2Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei 230031
Abstract： Influences of deoxygenation on the resistivity and the magnetic properties of
La0.7Ca0.3Mn0.92Cr0.08O3-δ(M = Al, Cr) are compared to understand the peculiar doping effect of chromium in the ferromagnetic manganites. It is found that the double resistivity bumps exhibited by the Cr-doped compounds can be tuned by the oxygen content. We have related the double-bump feature with the well-known inefficiency of Cr in lowering TC, and interpreted both the features consistently in terms of large-scale phase separation. It is suggested that the
large-scale phase separation is a general characteristic of Cr-doped manganites, and many unusual phenomena exhibited by Cr doping are directly related to the large-scale phase separation.
2004, Vol. 21 
