Coated particles yttrium basic carbonate

Using the same procedure, spherical nanosize particles of hematite were coated with yttrium basic carbonate and showed that various surface thermodynamic properties of these systems were essentially those of yttria (37). 

One important aspect of such coating processes is the generality of the procedure. It would appear that specific surface characteristics of the preformed particles are not necessarily essential for the successful deposition of the new layer. For example, yttrium basic carbonate coatings were produced on zirconium basic sulfate... 

Aiken B, Matijevic E (1988) Preparation and properties of uniform coated inorganic colloidal particles, 4. Yttrium basic carbonate and yttrium-oxide on hematite. J Colloid Interface Sci 126 645-649... 

Figure 2.28 Transmission electron micrograph of yttrium basic carbonate (YOHCO3) particles coated with Si02 showing (a) smooth Si02 coating when the reaction was carried out at room temperature and (b) rough Si02 coating formed at higher reaction temperature (SOT). (From Ref. 86.)...

In most cases the coating alone may be changed on subsequent treatments (e.g., by calcination at elevated temperatures), such as by converting basic carbonates into oxides. However, in some instances the shell and the core may interact to yield a different compound. For example, silica particles coated with Y(0H)C03 on heating to IOOO°C reacted to yield yttrium silicate, Y2Si207, which was restricted to the shell, as long as the amount of silica in the core was in molar excess (32). 

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