Atomic displacements and lattice distortion in the magnetic-field-induced charge ordered state of SmRu$_{4}$P$_{12}$

TL;DR

This study investigates atomic displacements and lattice distortions in SmRu4P12 during magnetic-field-induced charge ordering, revealing rhombohedral elongation and domain responses via x-ray diffraction.

Contribution

It provides detailed analysis of atomic displacements and lattice symmetry changes in SmRu4P12 under magnetic fields, highlighting the field-induced charge order and structural distortions.

Findings

Atomic displacements of Ru and P atoms linked to charge order.

Splitting of Bragg peaks indicates rhombohedral lattice distortion.

Domain responses correlate with magnetic moment directions.

Abstract

Structural properties of SmRu$_4$P$_{12}$ in the anomalous magnetic ordered phase between $T^*\sim 14 $ K and $T_{\text{N}}=16.5$ K in magnetic fields has been studied by x-ray diffraction. Atomic displacements of Ru and P, reflecting the field-induced charge order of the $p$ electrons, have been deduced by analyzing the intensities of the forbidden Bragg peaks, assuming a cubic space group $Pm\bar{3}$. Also, by utilizing high-resolution x-ray diffraction experiment, we observed a splitting of fundamental Bragg peaks, clarifying that the unit cell in the magnetic ordered phase is rhombohedral elongated along the $[1\, 1\, 1]$ axis. Responses of the rhombohedral domains to the magnetic field, which reflects the direction of the magnetic moment, is studied in detail.