The basic salt cobalt(II) hydroxide fluoride was obtained by partial hydrolysis of a 0.2M solution CoF2. Mixed Co(II)Cu(II) hydroxide fluorides with an isomorphic substitution of Co(II) by Cu(II) ions up to 20% were also prepared.
XRD data obtained on these compounds indicate that they are single-phase compounds, their X-ray powder patterns being almost
identical to the Co(OH)0.7F1.3 diagram, with Zn(OH)F-type structure. However, their stoichiometries are very close to Co1−xCux(OH)F (0≤x≤0.2).
Thermal analysis studies carried out up to 1273 K in still air or under dynamic vacuum conditions show that in air CoO or
a mixture of CoO and CuO is formed as final product. In vacuum, at high temperature, with a Ta heating surface, pure α-Co
or a mixture of α-Co and Cu is formed at about 973 K.