Open AccessSTUDY OF THE CHARACTERISTICS OF METALLIC ULTRA-FINE PARTICLES EMBEDDED IN HOST MEDIUM (I)——QUANTUM WELL DOT MODEL OF VLTRA-FINE PARTICLES
Author(s) -
Huang Jue-Hua,
Zheng Xue
Publication year - 1993
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.42.385
Subject(s) - quantum dot , electron , physics , work (physics) , radius , quantum , particle size , work function , fermi level , condensed matter physics , atomic physics , computational physics , quantum mechanics , chemistry , computer security , electrode , computer science
A quantum well dot model of ultra-fine particles (UFP) is presented in this paper. It is assumed that principal UFP characteristics are determined by non-localized electrons, which are restricted within a three-demensional potential well with finite depth (quantum well dot). Electronic characteristics are contributed by both of single-electron behavior and collective be-haviors. The electron energy spectrum is mainly determined by single-electron behavior. The model reflects the atomic properties, such as bulk work funtion, atomic radius and first ioni-zing energy value, and ignores the finer UFP structures. The approximation is proved rea-sonable. A number of useful formulae and predictions are derived. (1) The famous UFP cha-racteristics, quantum size effect and shell structures of electron energy spectrum, are derived from the quantum well dot model. (2) The UFP work function and Fermi-energy level, which is diffi-cult to be obtained by other models, are calculated. The formula that expresses the work func tion xarying with UFP size variation is derived, which explains well the experiments. The work function increases at first and then decreases gradually to bulk one with UFP size in-creasing. (3) The average energy space (AES) near Fermi- energy and the relationship bet-ween AES and electron interaction are derived. And the famous Kubo formula can be derived from quantum well dot model. (4) Finally, the model predicts the existence of electron energy subbands in UFP and semiconductor behavior of metallic UFP in some size. When particle size increases the sub-bands can not be discriminated and finally disappears, the particle shows complete bulk characteristics.