Thermal behavior of iron arsenides under non-oxidizing conditions

• Main Authors: Seitkan, Ainur, Lampronti, Giulio I., Widmer, Remo N., Casati, Nicola P. M., Redfern, Simon Anthony Turner
• Other Authors: Asian School of the Environment
• Format: Article
• Language: English
• Published: 2020
• Subjects: Science::Geology; Iron; Crystal Structure
• Online Access: https://hdl.handle.net/10356/145599
• Institution: Nanyang Technological University

Fe2As has been studied in situ by synchrotron powder X-ray diffraction (PXRD) over the range of temperatures 25–850 °C and under a neutral atmosphere to understand its thermal behavior, which is potentially important for gold extraction. For the first time, incongruent high-temperature reactions of Fe2As are observed as it breaks down and the existence of a previously undiscovered high-temperature FeAs phase with an NiAs-type structure has been determined experimentally. No evidence has been found for the existence of the high-temperature Fe3As2 phase. Hence, the previously published phase diagram for the Fe–As system has to be modified accordingly.