High-temperature Single-crystal X-ray Diffraction Research Articles

A gas-flow furnace for X-ray crystallography

A gas-flow furnace has been built for high-temperature single-crystal X-ray diffraction measurements using a Huber 512 four-circle goniometer. The furnace assembly is mounted on an XYZ stage which is fixed to the ϕ-axis counterbearing and the sample is mounted on the ϕ circle. The XYZ stage allows a determination of the temperature profile around the sample and a selection of the optimum furnace position. The sample temperature is measured with a thermocouple placed 0.5 mm from the center of the crystal. Thermocouple temperature was calibrated up to 991 K using the thermal expansion of a single-crystal of NaCl. The accuracy of the sample temperature measurements and the fluctuations of the sample temperature are both better than ± 2 K. The furnace has been successfully used to study the crystal structures and the thermal expansion of β-Mg2SiO4 up to 1100 K and the phase transitions in ilvaite, Ca(Fe2+ Fe3+) Fe2+Si2O7O(OH), and anorthite, CaAl2Si2O8, at 346 and 516 K, respectively.

High-temperature single crystal X-ray camera using an infrared thermal-image heating technique.

A high-temperature single crystal X-ray diffraction camera has been constructed by modifying an infrared thermal-image furnace. High temperatures (∼1700°C) can be readily attained by focussing radiation from a halogen lamp on a single crystal with a gold-plated internal ellipsoidal reflector. This camera has been used for examining the phase transformation and melting of orthopyroxene and proved to be useful for the study of the phase changes and the structure states of the produced phases in single crystals at high temperatures.

赤外線集中方式による単結晶用高温X線カメラ

A high-temperature single crystal X-ray diffraction camera has been constructed by modifying an infrared thermal-image furnace. High temperatures (∼1700°C) can be readily attained by focussing radiation from a halogen lamp on a single crystal with a gold-plated internal ellipsoidal reflector. This camera has been used for examining the phase transformation and melting of orthopyroxene and proved to be useful for the study of the phase changes and the structure states of the produced phases in single crystals at high temperatures.

A hemispherical furnace for high-temperature single crystal X-ray diffraction studies

A high-temperature furnace suitable for single-crystal X-ray diffraction studies has been designed and built. The furnace employs a set of three concentric beryllium hemispheres to provide a vacuum environment for the sample and to act also as a series of heat reflecting shields reducing radiative heat losses. The furnace can be operated from room temperature to at least 1000°C. With a special control circuit, the temperature can be held constant to ± 0.1 °C for extended periods of time. Thermal expansion data have been obtained for β-eucryptite (LiAlSiO4), beryl (Al2Be3Si6O18) and aluminium titanate (Al2TiO5).