Phase transition ball-milling

The S-form can be obtained by treating Copper Phthalocyanine Blue in benzene or toluene with aqueous sulfuric acid in the presence of a surfactant [21], The e-phase is produced by comminution of the a-, 7-, or 8-modification, for instance in a planetary ball mill. The mill base is then aftertreated in an organic solvent at elevated temperature. It is important to realize that the temperature, depending on the solvent, must be kept below the transition temperature at which the e-phase converts to the (3-modification (30 to 160°C). The e-modification is made best from the 7-phase, and the most preferred solvents are alcohols [22], For the industrially hitherto insignificant tt, X, and R-forms of Copper Phthalocyanine Blue (see [1], Vol. II, 34-35). 

Phase transitions with decreasing density were achieved also in experiments involving an irradiation of substances [238], ball milling of crystals [239, 240], and static compression with shear [241-243]. Each of these processes involves a partial or total amorphization of the solid, by generating numerous defects, creating ultra-tine particles with highly active surfaces, or causing plastic flows, respectively. 

Diaz-Guerra C, Montone A, Piqueras J, Cardellini F (2002) Structural and cathodoluminescence study of mechanically milled silicon. Semicond Sci Technol 17 77-82 Gaffet E, Harmelin M (1990) Crystal-amorphous phase transition induced by ball-milling in silicon. J Less Common Met 157 201-222... 

K. Morad, Kinetics of the phase transitions of lead(ll) fluoride on ball-milling, Concordia University, 2004. 

The dependence of the phase transformation temperature and sequence on the mill type, milling media, time, acceleration is analyzed in this chapter for a few samples of transition aluminas and their mixtures. Mechanical treatment carried out in the high-powerful planetary ball mills developed at the Institute of Solid State Chemistry SB RAS. Since it is known [10] that mechanical activation with and without elimination of heat leads to essentially different processes in the powder under activation, experiments were carried out with the oxides under investigation using mills both with and without aquatic cooling. 

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