金属中电子的施受交换键合

Bond of the Donation-accepting and Exchanging Electrons in the Metal

原子间相互交替施受或互换价电子是金属键合的基本模式。金属 Na 中某 A 原子可施舍或接受一个3s 电子,与其相邻的 B 原子则可接受或施舍一个3s 电子,使 A、B 原子核周围均获得封闭的电子组态。Hg 原子的电子外壳层己具有稳定的封闭状态,金属 Hg 中的相邻原子不能相互施受电子,只能互换电子。金属中的任何一个原子与其等同相邻的每一个原子有交替施受互换电子的同等机会。原属 A 原子的电子通过 A、B 原子间的施受交换过程可传递给 B 原子,再通过 B、C 原子间的施受交换过程又可转移给 C 原子,所以金属中的任何一个价电子并不始终处在定域化的束缚状态中。在外加电压的作用下可使无方向性的施受交换电子过程变成有方向性,即形成电流。价电子在原子表层中时的能量低于在晶格空隙中时的能量,在原子表层中出现的机率大于在晶格空隙中出现的机率,传导电子是沿着原子表层自一个原子越过原子面之间的间隙势垒进入另一个原子的表层的。

Metal atoms mutually donating and accepting or exchanging valence ele- ctrons are the fundamental modes of metal binding.Any atom in the metal possesses an equal probability of donating,accepting and exchanging electrons with each of its equality-adjacent atoms.An electron belonging to atom A can be transferred to atom B by donating,accepting or exchanging between atom A and B,and then it continues to be transferred to the next atom C from atom B by thesame way as between atoms A and B.Thus,any of the the valence electrons in the metal is not in a localization bound state from beginging to end.The applied external voltage on a metal results in originally non-directional donating-accepting-exchanging process of valence electrons becoming a directio- nal one.The energy of valence electrons in the outer layer of an atom is lower than in the gap of a crystal lattice,and the probability of valence electrons emerging in the outer lager layer of an atom is larger than that in the gap of a crystal lattice.Acoordingly,conduction electrons from the outer layer of an atom find their way to that of another atom by overcoming the gap pote- ntial hill between the outer layers of the both atoms.