Magnetic and electronic orderings in orthorhombicRMnO3(R=Tm, Lu) studied by resonant soft x-ray powder diffraction

Resonant soft x-ray powder diffraction experiments on orthorhombic TmMnO${}_{3}$ and LuMnO${}_{3}$ are presented. Experiments were performed in the vicinity of the Tm ${M}_{5}$ and the Mn ${L}_{2,3}$ edges to study the Tm and Mn magnetic moments, respectively. These experiments show that for the heavy rare-earth perovskite with an E-type ordered ground state, the Tm magnetic moments order already in the nonferroelectric incommensurate magnetic phase. Additionally, deviations from the collinear E-type Mn magnetic structure at low temperatures are found for both compounds. These experiments show the power of resonant soft x-ray diffraction, extended to polycrystalline 4$f$ materials.