概括
同时进行的X射线衍射和电阻研究证实了的存在.
科学领域:
- 固态物理 固态物理
- 材料科学是一种材料科学.
- 晶体学 晶体学是指结晶学.
背景情况:
- 布里奇曼之前的研究发现了在不同压力下的体积和电阻过渡.
- 这些转变与的结构变化之间的确切关系尚不清楚.
研究的目的:
- 为了阐明布里奇曼观察到的体积和的电阻转换之间的关系.
- 在高压下确定的晶体结构和晶格参数.
主要方法:
- 同时在高压下对进行了现场X射线衍射和电阻测量.
- 使用了高压电池和钻石形电池技术.
主要成果:
- 发现中78千巴 (千巴) 的电阻转变与59千巴 (千巴) 的体积转变相同.
- 在这种过渡过程中,从以身体为中心的立方体 (BCC) 结构转变为六角密集结构 (HCP).
- 精确的格子参数和压缩值被确定为高压时的HCP阶段,显示与以前报告的差异.
结论:
- 该研究明确地将的体积和电阻转换联系起来,将它们归因于单一的结构转换.
- 这些发现为压力下的提供了准确的结构数据,完善了以前的测量和了解其相位行为.
相关概念视频
Momentum And Radiation Pressure
An object absorbing an electromagnetic wave would experience a force in the direction of propagation of the wave. This force occurs because electromagnetic waves contain and transport momentum. The force accounts for the wave's radiation pressure exerted on the object. Maxwell's prediction was confirmed in 1903 by Nichols and Hull by precisely measuring radiation pressures with a torsion balance. The measuring instrument had mirrors suspended from a fiber kept inside a glass container. Nichols...
Radiation Pressure: Problem Solving
The radiation pressure applied by an electromagnetic wave on a perfectly absorbing surface equals the energy density of the wave. The wave's momentum also gets transferred to the surface when an electromagnetic wave is entirely absorbed by it. The rate at which momentum is transmitted to an absorbing surface perpendicular to the propagation direction equals the force on the surface.
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...


