Local lattice of the charge ordered La0.5Ca0.5MnO3 has been studied by temperature dependent Mn K-edge x-ray absorption measurements, using fluorescence detection method, to explore how the local lattice distortions are associated with the charge ordering in this system. The x-ray absorption near edge structure (XANES) reveals an abrupt change in the local MnO6 octahedral geometry across the charge ordering temperature. The extended x-ray absorption fine structure (EXAFS) analysis shows largely distorted MnO6 octahedra with coexisting Q3-type and Q2-type of Jahn-Teller (JT) modes at low temperature in the commensurate charge ordered phase. We find that small JT distortions persist also in the charge disordered phase at high temperature.
LOCAL STRUCTURE OF THE CHARGE ORDERED La0.5Ca0.5MnO3
2000
Abstract
Local lattice of the charge ordered La0.5Ca0.5MnO3 has been studied by temperature dependent Mn K-edge x-ray absorption measurements, using fluorescence detection method, to explore how the local lattice distortions are associated with the charge ordering in this system. The x-ray absorption near edge structure (XANES) reveals an abrupt change in the local MnO6 octahedral geometry across the charge ordering temperature. The extended x-ray absorption fine structure (EXAFS) analysis shows largely distorted MnO6 octahedra with coexisting Q3-type and Q2-type of Jahn-Teller (JT) modes at low temperature in the commensurate charge ordered phase. We find that small JT distortions persist also in the charge disordered phase at high temperature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
