“DistorX” program for analysis of structural distortions affecting X-ray diffraction patterns

L Kalinowski,A Ślebarski,J Goraus

doi:10.1063/1.5042654

Abstract

For the purposes of research on strongly correlated electronic systems (SCES), a computer program, DistorX (Distortion or X-ray diffraction patterns), was created. The program is an interactive Jupyter notebook for simulating the effects of structural distortions on X-ray diffraction patterns. The program is designed to be universal, in that it may be successfully applied to a variety of structures. In previous reports, a structural transition from a cubic phase of Yb3Rh4Sn13 – type to the superlattice variant was been observed at 160 K for a series of skutterudite-related Ce3M4Sn13 compounds, where M = Co, Ru or Rh. In this work, we use a specialized build of DistorX to simulate the low-temperature X-ray diffraction patterns of a distorted unit cell. The method described here obtains simulated XRD patterns from the atomic positions and permits investigation of crystal structure without imposed symmetry operations. We further indicate the crystallographic plane in which the distortion occurs, and explain the possible origin of CDW in these materials.

Highlights

INTRODUCTIONCe3Co4Sn13, experience charge density waves with accompanying structural distortions.[7] Here, we compare the low temperature x-ray diffraction patterns to DistorX simulations, considering structural distortion caused by a charge density wave
Filled skutterdites with a chemical formula R3M4Sn13, where R is rare earth atom, and M is Co, Ru or Rh, have been extensively investigated due to their diverse heavy fermion properties and interesting interplay between superconductivity, magnetic order and thermoelectric properties, which are closely related to the cage-type structure.[1]
This result is further consistent with the presence of a superlattice variant with a double c lattice parameter seen in experimental data, and may confirm that the structural phase

Summary

INTRODUCTION

Ce3Co4Sn13, experience charge density waves with accompanying structural distortions.[7] Here, we compare the low temperature x-ray diffraction patterns to DistorX simulations, considering structural distortion caused by a charge density wave. This structural phase transition has been observed recently at T D ∼ 160 K for other Ce3Ru4Sn13 and Ce3Rh4Sn13 compounds,[8] similar to CDW-type ordering suggested by Song et al 2003.9 We further investigate the effect of CDW structural change on diffraction patterns of Ce3M4Sn13. The observed structural disorder appears to be essential to understanding the competition between superconductivity and CDW in the family of La-based R3M4Sn13 compounds,[10] as well as the nature of structural quantum phase transitions at T D → 0

EXPERIMENTAL DETAILS

CDW SIMULATION METHOD

RESULTS AND DISCUSSION

CONCLUSIONS