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Work function changes in the double layered manganite La1.2Sr1.8Mn2O7

K. Schulte·M. A. James·L. H. Tjeng·P. G. Steeneken·G. A. Sawatzky·R. Suryanarayanan·G. Dhalenne·A. Revcolevschi
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Abstract

We have investigated the behaviour of the work function of La1.2Sr1.8Mn2O7 as a function of temperature by means of photoemission. We found a decrease of 55 +/- 10 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 by Furukawa, but are consistent with other measurements. The disagreement with double-exchange can be explained using a general thermodynamic relation valid for second order transitions and including the extra processes involved in the manganites besides double-exchange interaction.

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K. Schulte, M. A. James, L. H. Tjeng, P. G. Steeneken, G. A. Sawatzky, R. Suryanarayanan, G. Dhalenne, A. Revcolevschi. 2001-05-28. Work function changes in the double layered manganite La1.2Sr1.8Mn2O7. https://doi.org/10.1103/physrevb.64.134428

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