Coexistence of large and small polarons in manganites

被引:17
作者
Cataudella, V [1 ]
De Filippis, G [1 ]
Iadonisi, G [1 ]
机构
[1] Univ Naples Federico II, Dipartimento Sci Fis, INFM, Unita Napoli, I-80125 Naples, Italy
关键词
D O I
10.1103/PhysRevB.63.052406
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The interplay of the electron-phonon interaction and of the double- and superexchange magnetic effects is analyzed in the La1-xCaxMnO3 perovskites with 0<x<0.5. By using an analytical variational scheme that allows us to treat the electron-phonon interaction in a fully quantum manner it is shown that in the intermediate electron-phonon coupling regime a charge-density instability occurs near the metal-insulator transition, induced by either temperature or hole doping. The system segregates in antiferromagnetic or paramagnetic small polarons and ferromagnetic large polaron domains characterized by different values of the lattice distortions that are satisfactory compared with those experimentally observed.
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页数:4
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