Investigation of activated transport in hole doped rare earth manganites in the high temperature paramagnetic regime

• Published in: Solid state communications 2006-05, Vol.138 (6), p.318-323
• Main Authors: Jain, Himanshu, Raychaudhuri, A.K., Mukovskii, Ya.M., Shulyatev, D.
• Format: Article
• Language: English
• Subjects: A. Rare earth manganites; D. Electronic transport
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2006.01.039

Electronic transport in the high temperature paramagnetic regime of the colossal magnetoresistive oxides, La 1− x A x MnO 3, A=Ca, Sr, Ba, x≃0.1–0.3, has been investigated using resistivity measurements. The main motivation for this work is to relook into the actual magnitude of the activation energy for transport in a number of manganites and study its variation as a function of hole doping ( x), average A-site cation radius (〈 r A〉), cationic disorder ( σ 2) and strain ( ε zz ). We show that contrary to current practice, the description of a single activation energy in this phase is not entirely accurate. Our results clearly reveal a strong dependence of the activation energy on the hole doping as well as disorder. Comparing the results across different substituent species with different 〈 r A〉 reveals the importance of σ 2 as a metric to qualify any analysis based on 〈 r A〉.