X-ray diffraction measurements of the c-axis Debye-Waller factors of YBa2Cu3O7 and HgBa2CaCu2O6

TL;DR

This study uses x-ray diffraction to measure the temperature-dependent c-axis Debye-Waller factors in high-temperature superconductors, revealing smooth behavior across the transition temperature and providing insights into lattice dynamics.

Contribution

First application of x-ray diffraction to measure c-axis Debye-Waller factors in high-Tc superconductors, showing no anomalies at T_c.

Findings

Debye-Waller factors vary smoothly through T_c

Heavy element displacements show no anomalies at superconducting transition

Method complements other techniques for lattice dynamics analysis

Abstract

We report the first application of x-rays to the measurement of the temperature dependent Bragg peak intensities to obtain Debye-Waller factors on high-temperature superconductors. Intensities of (0,0,l) peaks of YBa2Cu3O7 and HgBa2CaCu2O6 thin films are measured to obtain the c-axis Debye-Waller factors. While lattice constant and some Debye-Waller factor measurements on high Tc superconductors show anomalies at the transition temperature, our measurements by x-ray diffraction show a smooth transition of the c-axis Debye-Waller factors through T$_c$. This suggests that the dynamic displacements of the heavy elements along the c-axis direction in these compounds do not have anomalies at Tc. This method in combination with measurements by other techniques will give more details concerning dynamics of the lattice.