Title :
Structure effect on the polarons in La/sub 0.7/Ca/sub 0.3-x/Ba/sub x/MnO/sub 3/ manganites
Author :
Ulyanov, A.N. ; Dong-Seok Yang ; Seong-Cho Yu
Author_Institution :
Dept. of Phys., Chung-Buk Nat. Univ., Cheongju, South Korea
Abstract :
Summary form only given. Electron-phonon interaction plays a significant role in forming of colossal magnetoresistance effect (CMR). A local probe as given by the extended X-ray absorption fine structure (EXAFS) is an useful tool to study the polaronic charge and it variation on temperature and ionic size. Here we present a study of polaronic charge and its variation at the concentration structural orthorhombic (x=0; 0.03; 0.06)-rhombohedral (x=0.09; 0.12; 0.3) phase transition in La/sub 0.7/Ca/sub 0.3-x/Ba/sub x/MnO/sub 3/ manganites by Mn K-edge EXAFS measurement on single phase powders synthesized by solid state reaction method. EXAFS spectra were analyzed by the conventional method and using the regularization technique the atomic pair distribution functions (PDF) for Mn-O distances were obtained.
Keywords :
EXAFS; barium compounds; bond lengths; calcium compounds; colossal magnetoresistance; electron-phonon interactions; ferromagnetic materials; lanthanum compounds; polarons; solid-state phase transformations; EXAFS; La/sub 0.7/Ca/sub 0.3-x/Ba/sub x/MnO/sub 3/; Mn-O distances; atomic pair distribution functions; colossal magnetoresistance effect; electron-phonon interaction; extended X-ray absorption fine structure; polaronic charge; regularization technique; solid state reaction method; Charge carrier processes; Charge measurement; Colossal magnetoresistance; Current measurement; Electromagnetic wave absorption; Phase measurement; Powders; Probes; Solid state circuits; Temperature;
Conference_Titel :
Magnetics Conference, 2002. INTERMAG Europe 2002. Digest of Technical Papers. 2002 IEEE International
Conference_Location :
Amsterdam, The Netherlands
Print_ISBN :
0-7803-7365-0
DOI :
10.1109/INTMAG.2002.1001324
