In:
Applied Physics Letters, AIP Publishing, Vol. 93, No. 15 ( 2008-10-13)
Abstract:
Using in situ synchrotron measurements of total reflection x-ray fluorescence, we find evidence of strontium surface segregation in (001)-oriented La0.7Sr0.3MnO3 thin films over a wide range of temperatures (25–900 °C) and oxygen partial pressures (pO2=0.15–150 Torr). The strontium surface concentration is observed to increase with decreasing pO2, suggesting that the surface oxygen vacancy concentration plays a significant role in controlling the degree of segregation. Interestingly, the enthalpy of segregation becomes less exothermic with increasing pO2, varying from −9.5 to −2.0 kJ/mol. In contrast, the La0.7Sr0.3MnO3 film thickness and epitaxial strain state have little impact on segregation behavior.
Type of Medium:
Online Resource
ISSN:
0003-6951
,
1077-3118
Language:
English
Publisher:
AIP Publishing
Publication Date:
2008
detail.hit.zdb_id:
211245-0
detail.hit.zdb_id:
1469436-0
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