Theory of the unusual doping and temperature dependence of photoemission spectra in manganites
Year: 2008
Type: article
Abstract: 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 t 2 g 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 .
Source: Europhysics Letters (EPL)
Authors: Prabuddha Sanyal, Subhra Sen Gupta, Nandan Pakhira, H. R. Krishnamurthy, D. D. Sarma, T. V. Ramakrishnan
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2013064540