24小时热门版块排行榜    

查看: 1236  |  回复: 8
当前主题已经存档。
当前只显示满足指定条件的回帖,点击这里查看本话题的所有回帖

shary_hua

木虫 (正式写手)

[交流] 纳米材料中常提到的Superlattice是什么意思!

纳米材料中常提到的Superlattice是什么意思!期盼各位给以解答!谢谢!
回复此楼

» 猜你喜欢

» 本主题相关商家推荐: (我也要在这里推广)

已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

shary_hua

木虫 (正式写手)

感谢meiniaike 最短时间内给予的及时帮助!
还要继续麻烦了!
超晶格与通常所说的晶格有什么区别么?
3楼2008-01-09 17:21:20
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 9 个回答

meiniaike

铁杆木虫 (正式写手)

超晶格,指一种周期性阵列
2楼2008-01-09 17:04:17
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

bachier

金虫 (职业作家)

呵呵

★ ★
NJUT_tiger(金币+2,VIP+0):好~~
超晶格,在纳米材料里,好像就是指纳米颗粒堆积成周期性排列的结构,这些结构和晶体内部,原子的排列有相似性
晶格,就是专门原子周期性排列构成的晶体的结构了
4楼2008-01-09 19:35:37
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

bachier

金虫 (职业作家)

详细概念

A superlattice is a material with periodically alternating layers of several substances. Such structures possess periodicity both on the scale of each layer's crystal lattice and on the scale of the alternating layers. Semiconductor superlattices were first grown in the 70's and metallic superlattices in 1980.

Superlattices can be produced in a number of ways, but the most common are Molecular-beam epitaxy and Sputtering. With these methods lattices as thin as a few atomic layers can be produced. One nomenclature used to describe the produced superlattice is [Fe20V30]20 signifying a bi-layer consisting of 20Å of Iron (Fe) followed by 30Å of Vanadium (V), the whole structure repeated 20 times yielding a total thickness of 1000Å or 100nm.

The structural quality of the produced superlattices can be verified by means of X-ray diffraction which give rise to characteristic satellite peaks. The same applies to Neutron diffraction. Other effects of the alternating layering are: Giant magnetoresistance, tunable reflectivity for X-ray and Neutron mirrors, neutron spin polarization, and changes in the elastic and acoustic properties. Depending on the nature of components, a superlattice may be called magnetic, optical or semiconductor.

The motion of charge carriers in a superlattice is modified with respect to each individual lattice. This can lead to significant increase of carrier mobility (used in microwave devices) or special optical features (such as a semiconductor laser).
There also exists a class of quasiperiodic superlattices named after Fibonacci. The Fibonacci superlattices are usually studied as a single-dimensional model of quasicrystal, where either electron hopping transfer interactions or on-site energies take two values arranged in a Fibonacci sequence.
5楼2008-01-09 19:46:44
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
普通表情 高级回复 (可上传附件)
信息提示
请填处理意见