Influence of Microwave Treatment on the Dehydration of Crystallohydrates of Iron, Cobalt and Nickel Flourides

Dehydration Pathway of CoF2·4H2O Revisited by Integrated ex Situ and in Situ Calorimetric and Structural Studies

“…The existence of a CoF 2 ·0.5H 2 O to α-CoF 2 reaction and a stable intermediate CoF 2 ·0.5H 2 O phase is clearly identified by our integrated kinetic analysis and structural investigation. Although Berdonosov et al using a thermogravimetric method reported CoF 2 ·0.9H 2 O, not seen here, they described the existence of a similar intermediate phase of CoF 2 ·0.4H 2 O . It is possible that Berdonosov et al’s CoF 2 ·0.4H 2 O might actually be the CoF 2 ·0.5H 2 O phase that we have identified here.…”

“…Moreover, ex situ and in situ analyses usually lead to different conclusions. In 2008, Berdonosov et al, using thermogravimetric analysis (TGA), reported a three-step mechanism in which no water loss was seen below 120 °C, followed by the loss of about three water molecules to CoF 2 ·0.9H 2 O up to 310 °C and the loss of about one-half a water molecule to CoF 2 ·0.4H 2 O up to 440 °C, and finally, complete loss of crystalline water at 500 °C . In 2016, Nasriddinov et al, using nonequilibrium and equilibrium tensiometry with a membrane null manometer, reported a two-step decomposition mechanism including dehydration to the intermediate CoF 2 ·H 2 O at 72 °C and complete dehydration at 107 °C .…”

Synthesis of NiF2 and NiF2·4H2O Nanoparticles by Microemulsion and Their Self-Assembly

“…The as-synthesized NiF 2 ·4H 2 O nanomaterials were transformed to anhydrous NiF 2 by an original conversion method under gaseous molecular fluorine (F 2 ) while preserving their self-assembly. The transformation is achieved at a significantly lower temperature than previously reported …”