Jinglian Du

Electrochemical Potential Derived from Atomic Cluster Structures

Based on the atomic cluster structures and free electron approximation model, it is revealed that the electrochemical potential (ECP) for the system of interest is proportional to the reciprocal of atomic cluster radius squared, i.e., φ = k·(1/r(2)). Applied to elemental crystals, the correlation between atomic cluster radii and the ECP that we have predicted agrees well with the previously reported results. In addition, some other physicochemical properties associated with the ECP have also been found relevant to the atomic cluster radii of materials. Thus, the atomic cluster radii can be perceived as an effective characteristic parameter to measure the ECP and related properties of materials. Our results provide a better understanding of ECP directly from the atomic structures perspective.

Phase stability limit of c-BN under hydrostatic and non-hydrostatic pressure conditions

Phase stability limit of cubic boron nitride (c-BN) has been investigated by the crystal structure search technique. It indicated that this limit is ∼1000 GPa at hydrostatic pressure condition. Above this pressure, c-BN turns into a metastable phase with respect to rocksalt type boron nitride (rs-BN). However, rs-BN cannot be retained at 0 GPa owing to its instability at pressure below 250 GPa. For non-hydrostatic pressure conditions, the phase stability limit of c-BN is substantially lower than that under hydrostatic pressure conditions and it is also dramatically different for other pressure mode.

Hidden electronic rule in the “cluster-plus-glue-atom” model

Electrons and their interactions are intrinsic factors to affect the structure and properties of materials. Based on the “cluster-cluster-plus-glue-atom” model, an electron counting rule for complex metallic alloys (CMAs) has been revealed in this work (i. e. the CPGAMEC rule). Our results on the cluster structure and electron concentration of CMAs with apparent cluster features, indicate that the valence electrons’ number per unit cluster formula for these CMAs are specific constants of eight-multiples and twelve-multiples. It is thus termed as specific electrons cluster formula. This CPGAMEC rule has been demonstrated as a useful guidance to direct the design of CMAs with desired properties, while its practical applications and underlying mechanism have been illustrated on the basis of CMAs’ cluster structural features. Our investigation provides an aggregate picture with intriguing electronic rule and atomic structural features of CMAs.