Polarons and isotope effect in manganites

✍ Scribed by E.L. Nagaev

• Book ID: 104337467
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 81 KB
• Volume: 258
• Category: Article
• ISSN: 0375-9601
• DOI: 10.1016/s0375-9601(99)00293-5

✦ Synopsis

Numerical estimates are carried out which show that the polaronic effects cannot be an origin of specific properties of the CMR materials. A quantum-mechanical calculation of the charge carrier band narrowing with increasing temperature is carried out for the double-exchange systems. Comparing its results with experimental data shows that the hole-phonon coupling in them is too weak for the small polaron formation. Despite this, a giant isotope effect is possible in the manganites due to an isotope dependence of the nonstoichiometry of manganites, to which lattice vibrations contribute considerably.