A diamond cell for x-ray diffraction studies at high pressures

Abstract

A high pressure X-ray powder camera has b een constructed. The instrumen t has been found to be usefu l for rout ine X-ray work, using molybdenum radiation, to pressures of approximately 60 kilobars. Previously repo l ted transitions have been observed in s ilver iodide, potassium iodide, bismu th , and t hallium. The high pressure forms and lattice parameters were found to be: AgI-f.c. c. (NaCI ty pe), ao = 6.067 A; KI-s.c. (CsCI type), ao = 4.093 A; Tl-f.c.c. (NaCl type) , ao = 4.778 A; Bi structure not d etermined . These data confirm previous reports en the high press ure forms of AgI and KI. D ata on T l and B i are al)parently reported for the first time. The high pressure mod ifi cations were stud ied at the fo ll owing approximate press ures whieh are not ind icative of the point where t he transition occurs: AgI-3.3 kilobars, KI-20 kilobars, Bi-28 kilobars, and Tl-60 kilobars-;l