Lattice Thermal Expansion and Ionicity for III2–VI3 Binary Defect Tetrahedral Compound Semiconductors and Their Alloys

Abstract

A model for calculating the lattice thermal expansion is modified to be applicable to binary defect tetrahedral compounds that belong to the III 2 -VI 3 group. The number of valence electrons for the expected missing atom as a vacancy is used to correlate the deviations caused by the ionicity of this group of compounds. The ionicity effects which are due to the different numbers between vacancy atom types, which in this case is the group III element, and the element itself, were also added to the correlation equation. In general, the lattice thermal expansion for a compound semiconductor can be calculated from a relation containing the melting point, the mean atomic distance, and the number of valence electrons for the atoms forming the compound. For compounds that undergo a structural change during heating, the phase transition temperature has the same role as the melting point for calculating the lattice thermal expansion that belongs to the related structure phase. The value of the mean ionicity for this group of compounds is also calculated and found to be equal to 0.416.

Models for mean bonding length, melting point and lattice thermal expansion of nanoparticle materials

“…In general, as reported in a previous work [18], the melting point of materials has a great effect on the material properties and their applications. In this section, attempts are made to apply the effects of lattice volume in the Yang et al model [17], to improve the calculation of the melting point of nanoscale size materials.…”

Critical Size Structure Parameters for Au Nanoparticles

“…The change of one or both of these two factors means that the material structure is changed. Moreover, for bulk crystals, both of them may undergo changing [1]. In general, the crystal structure of a solid undergoes a phase transition due to temperature or pressure change [1].…”

“…Moreover, for bulk crystals, both of them may undergo changing [1]. In general, the crystal structure of a solid undergoes a phase transition due to temperature or pressure change [1]. For nanocrystals smaller than 4 nm, most of the materials are undergo changing in their crystal structures [2].…”