Year: 2001
Type: article
Abstract: We have investigated the behavior of the work function of ${\mathrm{La}}_{1.2}{\mathrm{Sr}}_{1.8}{\mathrm{Mn}}_{2}{\mathrm{O}}_{7}$ as a function of temperature by means of photoemission. We found a decrease of $55\ifmmode\pm\else\textpm\fi{}10\mathrm{meV}$ in going from 60 K to just above the Curie temperature (125 K) of the sample. Above ${T}_{C}$ the work function appears to be roughly constant. Our results are exactly opposite to the work function changes calculated from the double-exchange model [N. Furukawa, J. Phys. Soc. Jpn. 66, 2528 (1997)] but are consistent with other data. The disagreement with double exchange can be explained using a general thermodynamic relation valid for second order transitions [D. van der Marel and G. Rietveld, Phys. Rev. Lett. 69, 2575 (1992); D. van der Marel, D. I. Khomskii, and G. M. Eliashberg, Phys. Rev. B 50, 16 594 (1994)] and including the extra processes involved in the manganites besides double-exchange interaction.
Authors: K. Schulte, M. A. James, L. H. Tjeng, P. G. Steeneken, G. A. Sawatzky, R. Suryanarayanan, G. Dhalenne, A. Revcolevschi
Language: Latvian
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1532533477