Application of Mythen Detector In-situ XRD Study on The Thermal Expansion Behavior of Metal Indium

TL;DR

This study uses in-situ XRD with a Mythen detector to analyze the nonlinear thermal expansion of indium, revealing anisotropic behavior near melting point and demonstrating the technique's effectiveness for real-time structural analysis.

Contribution

First application of in-situ time-resolved XRD with a Mythen detector to study indium's thermal expansion, showing nonlinear behavior and structural evolution close to melting.

Findings

Indium's a-axis expands biquadratically with temperature.

c-axis contracts cubically as temperature increases.

No phase change detected up to melting point.

Abstract

A Mythen detector has been equipped at the beamline 4B9A of Beijing Synchrotron Radiation Facility, which can be used for in-situ real-time measurement of X-ray diffraction (XRD) full profiles. In this paper, the thermal expansion behavior of metal indium has been studied by using the in-situ XRD technique with the Mythen detector. The indium film was heated from 30 to 160 {\deg}C with a heating rate of 2 {\deg}C/min. The in-situ XRD full-profiles were collected with a rate of one profile per 10 seconds. Rietveld refinement was used to extract the structural parameters. The results demonstrate that the thermal expansion of metal indium is nonlinear especially when the sample temperature was close to its melting point (156.5 {\deg}C). The expansion of a-axis and the contraction of c-axis of the tetragonal unit cell of metallic indium can be well described by biquadratic and cubic polynomials, respectively. The tetragonal unit cell presents a tendency to become cubic one with the increase of temperature but without detectable phase change. This study is not only beneficial to the application of metal indium, but also exhibits the capacity of in-situ time-resolved XRD experiments at the X-ray diffraction station of BSRF.