Experimental techniques of high-resolution inelastic X-ray scattering measurements for supercritical metallic fluids at high temperature and high pressure using synchrotron radiation at SPring-8

Inui Inui,Baron Baron,Tamura Tamura,Matsuda Matsuda,Ishikawa Ishikawa

doi:10.5488/cmp.11.1.83

Abstract

Received November 2, 2007 We have conducted high-resolution inelastic X-ray scattering (IXS) measurements of supercritical metallic fluids at high temperature and high pressure using synchrotron radiation at SPring-8 in Japan. We developed a high-pressure vessel for IXS measurements pressurized by He gas up to 196 MPa and installed the highpressure gas apparatus in the experimental hutch. After the installation IXS experiments were carried out for supercritical fluid Hg to study atomic dynamics in the metal-nonmetal transition near the liquid-vapor critical point. Next the apparatus is used to study atomic dynamics in the semiconductor-metal transition in supercritical fluid Se. In this article we report the experimental technique at high temperature and high pressure in detail, and show recent results using the technique.

Highlights

Understanding atomic dynamics in liquids is an important subject in physics in the twenty-first century
In this paper we describe the experimental technique under the extreme condition at high temperature and high pressure, using synchrotron radiation at the super-photon ring operating at 8 GeV (SPring-8) in Japan
In this article we describe the experimental technique for inelastic X-ray scattering (IXS) studies of supercritical metallic fluids at high temperature and at high pressure

Summary

Introduction

Understanding atomic dynamics in liquids is an important subject in physics in the twenty-first century. It is obvious that information on the atomic arrangement in these metallic fluids is quite important for the understanding of the mechanism of the metal-non-metal (M–NM) transition Structural studies such as diffraction experiments of supercritical metallic fluids are not so easy because the critical temperature and pressure are very high compared to those for molecular fluids as indicated in table 1. About two decades ago Tamura and Hosokawa developed a high-pressure vessel with Be windows and a specially designed sapphire cell for X-ray diffraction measurements of supercritical fluid Hg [8] This technique has been widely applied to a variety of structural studies for metallic fluids at high temperature and high pressure, and the quality of the data has been much improved using synchrotron radiation as seen in the reference [9]. As examples of the application of the technique, we present the results of supercritical fluid Hg and a preliminary result of supercritical fluid Se

High pressure gas apparatus for IXS measurements

Examples of IXS studies using the present technique

A preliminary result of expanded fluid Se

Summary