Sanyal, Prabuddha and Gupta, Subhra Sen and Pakhira, Nandan and Krishnamurthy, HR and Sarma, DD and Ramakrishnan, TV (2008) Theory of the unusual doping and temperature dependence of photoemission spectra in manganites. In: EPL: Europhysics Letters, 82 (4).
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A recent, major, puzzle in the core-level photoemission spectra of doped manganites is the observation of a 1–2 eV wide shoulder with intensity varying with temperature T as the square of the magnetization over a T scale of order 200 K, an order of magnitude less than electronic energies. This is addressed and resolved here, by extending a recently proposed two-fluid polaron–mobile electron model for these systems to include core-hole effects. The position of the shoulder is found to be determined by Coulomb and Jahn-Teller energies, while its spectral weight is determined by the mobile electron energetics which is strongly T and doping dependent, due to annealed disorder scattering from the polarons and the t2g core spins. Our theory accounts quantitatively for the observed T dependence of the difference spectra, and furthermore, explains the observed correspondence between spectral changes due to increasing doping and decreasing T.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to EDP Sciences.|
|Department/Centre:||Division of Chemical Sciences > Solid State & Structural Chemistry Unit|
|Date Deposited:||04 Jun 2010 06:13|
|Last Modified:||19 Sep 2010 05:59|
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