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.