Synchrotron X-ray study of the electron density in RFeO3 (R = Nd, Dy)

Abstract

Structure factors for small hydrothermally grown orthorhombic neodymium and dysprosium iron oxides RFeO3 (R = Nd, Dy) were measured with focused λ = 0.84 Å synchrotron radiation using a fast avalanche photodiode (APD) counter. Higher symmetry in the deformation electron density (Δρ) maps reflects the coordination of the magnetic atoms in the structure and implies that Δρ is sensitive to the cation–cation magnetic interactions. Within a given compound the local Δρ topographies around the R and Fe atoms are similar, but differ markedly between compounds. The difference in Δρ near the Nd and Dy atoms is associated with the different type of spin reorientation transitions in these compounds. The R–Fe magnetic interactions determine the magnetic phase transitions and consequently affect the electron distribution. Synchrotron radiation diffraction imaging of the electron density provides an additional tool for probing the magnetic properties of materials.