High-pressure phase transitions and equation of state of the III-V compound InAs up to 27 GPa

The III-V semiconductor compound InAs has been studied under high pressure in a diamond-anvil cell up to 27 GPa by energy-dispersive x-ray diffraction using the Cornell High Energy Synchrotron Source (CHESS). It shows the zinc-blende--to--rocksalt transformation at (7±{}0.2) GPa and a further transformation at (17±{}0.4) GPa to a {β}-Sn--type structure with increasing pressure. The zinc-blende--to--rocksalt phase transition which is associated with metallization is accompanied by a 17% volume collapse while the rocksalt to the {β}-Sn transformation has no volume discontinuity within experimental errors. This structural sequence is the same as that observed in several II-VI compounds under high pressures. The results are discussed in view of theoretical pseudopotential total-energy calculations of III-V compounds in various phases and comparison is made with available experimental data on InP and InSb.