A model based on the two film approximation is proposed for the description of the kinetics of the hydrogen isotope exchange between CHCl3 and DzO. In this model, details of mass transfer in interfacial region between the two liquid phases are considered and the kinetics of the exchange reaction is
Effect of disorder and isotope on the properties of a two orbital double exchange system
โ Scribed by A.N. Das; Manidipa Mitra
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 294 KB
- Volume
- 404
- Category
- Article
- ISSN
- 0921-4526
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โฆ Synopsis
A two-site single electron double exchange model incorporating orbital degeneracy, superexchange and electron-phonon (e-ph) interaction is studied using exact diagonalization method. The core spins are treated quantum mechanically. We study the ground state phase diagram as well as the magnetic susceptibility and the kinetic energy of the system as a function of temperature. Effect of difference in site energies, which mimics the role of site-diagonal disorder, is investigated. The susceptibility shows a peak at a characteristic temperature which we have referred to as T 0 . The variation of T 0 with e-ph coupling and that of the isotope-shift exponent รฐaร with T 0 are obtained. We also investigate the fieldinduced change in the kinetic energy, which is related to the colossal magnetoresistance (CMR) of the system, and find that the disorder enhances the CMR even for the two-site system.
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