December 2007

Journal

Incommensurate Charge Order Phase in Fe2OBO3 due to Geometrical Frustration

By:
Angst, Niklaus M; Hermann, Raphael; Schweika, Werner; Kim, Jong-Woo; Khalifah, Peter; Xiang, H. J.; Whangbo, M.-H.; Kim, Dae Ho ; Sales, Brian C; Mandrus, David
Journal Name:
Physical Review Letters
Page Number:
256402-1-256402-4
Volume:
99
Issue Number:
25
Publication Date:
December 2007

Abstract

The temperature dependence of charge order in Fe$_2$OBO$_3$ was investigated by resistivity and differential scanning calorimetry measurements, M"ossbauer spectroscopy, and synchrotron x-ray scattering, revealing an intermediate phase between room temperature and $340,{rm K}$, characterized by coexisting mobile and immobile carriers, and by incommensurate superstructure modulations with temperature-dependent propagation vector $(frac{1}{2},0,tau)$. The incommensurate modulations arise from specific anti-phase boundaries with low energy cost due to geometrical charge frustration.