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Effects of counterions on the change in the magnetic behavior due to mechanical amorphization have been examined on iron(II) complexes with 1,10-phenanthroline, Fe(phen)2(NCS)2, [Fe(phen)3](NCS)2·H2O, and [Fe(phen)3](PF6)2, at temperatures between 2 K and 300 K. Amorphization results in the increase in χMT, where χMis molar magnetic susceptibility and Tis temperature, in two modes, i.e., a jump at temperatures below 20 K and a subsequent gradual increase. The first mode is attributed to the mechanically induced high spin state (5T2g) which is made metastable below 20 K. The second is the thermally induced transition from a low spin (1A1g) to a high spin (5T2g) state for the distorted complexes with the widened distribution of the ligand field strength. The stabilization of the HS state is mainly due to the ligand field distortion caused by mechanical amorphization. Coordination of ionic species, NCS−and PF−6, originally serving as counterions, plays a significant role in the ligand field distortion.

Ball-milling of mixed gel derived from a simple mixing of component alkoxides increased the compositional microhomogeneity, judged quantitatively by high-resolution microprobe chemical analysis. At the same time, the particle size of PbTiO3obtained after calcination at 1023 K for 2 hr in air decreased, approaching those of oxide fine particles delivered from a bidentate alkoxide through an identical thermal treatment.

Dehydration and crystallization processes of vanadium pentoxide xerogels, V2O5· 1.6H2O, with and without preliminary mechanical pretreatment, were examined by thermal and structural analyses. During the final step of dehydration of as-prepared xerogel, crystallization into orthorhombic V2O5took place slowly but in one step, with a certain period of coexistence of the starting layer structure. The mechanically pretreated xerogel, in contrast, crystallized itself in two steps with a separated nucleation and growth, and allowed a smaller period of coexistence with the layer structure. These phenomena are associated with the disproportionation of the bonding state of interfoliar H2O.