Chemical compression and ferroic orders in La substituted BiFeO3

Chemical compression effects on the ferroic orders in La substituted BiFeO3 are studied by atomic pair distribution function analysis and structure modeling. While rhombohedral BiFeO3 exhibits ferroelectricity and antiferromagnetism (AF) with a cycloidal Fe spin arrangement leading to zero magnetization, La substituted BiFeO3 exhibits a reduced lattice polarization, strengthened AF order, and an apparently suppressed spin cycloid leading to nonzero magnetization. The observed changes in the ferroic orders arise from the chemical compression induced changes in the octahedral rotation and ferroelectric displacement of Bi atoms, which appear as lattice degrees of freedom entangling the electronic and magnetic orders in BiFeO3.

Automated summary

Chemical compression effects on the ferroic orders in La substituted BiFeO3 were investigated using atomic pair distribution function analysis and structure modeling. The results showed that La substitution led to a reduction in lattice polarization, a strengthening of antiferromagnetic order, and a suppression of spin cycloid, resulting in nonzero magnetization. These changes in the ferroic orders were attributed to the chemical compression-induced alterations in octahedral rotation and ferroelectric displacement of Bi atoms, which acted as lattice degrees of freedom entangling the electronic and magnetic orders in BiFeO3.