MECHANOCHEMICAL REACTIONS OF ALKALI METAL-HALIDES - THE SYSTEMS AX/BX/(H2O) WITH A, B = NA, K, RB, CS AND X = CL, BR, I

Solid solutions (K, Rb)X with X = Cl, Br, I are obtained by grinding mixtures of KX and RbX in a ball mill. The reaction can be accelerated by adding a small amount of water. When grinding CsCl and NaCl or CsBr and NaBr together with a stoichiometric amount of water in the ratio 1:2:2 double salts Cs(Na · H2O)2X3 (X = Cl, Br) are obtained. Above 40°C or 70°C, respectively they are partially dehydrated, yielding solid solutions Cs1-x(Na · H2O)xX. For both phases the enthalpies of formation from the binary halides were measured by solution calorimetry. They are negative. © 1990.