Phase-change materials: The view from the liquid phase and the metallicity parameter
Phase-change materials: The view from the liquid phase and the metallicity parameter
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DOI：
10.1557/mrs.2019.207
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发表时间：
2019-09
期刊：
影响因子：
5
通讯作者：
Shuai Wei;P. Lucas;C. Angell
中科院分区：
文献类型：
--
作者：
Shuai Wei;P. Lucas;C. Angell
虽然基于相变材料（pcm）的快速开关可重写非易失性存储单元已经在英特尔（Intel）等主要技术公司生产（目前可用的芯片为16 - 64gb），但对决定其成功的物理因素的深入了解仍然缺乏。最近，我们认为液相金属到半导体的转变（M-SC），位于离熔点t_m不远的地方，是必不可少的。M-SC本身是原子重排的结果，涉及到一个脆弱到强粘度的转变，控制着结晶的速度和半导体状态的稳定。在这里，我们回顾了过去的工作，并引入了一个新的参数，“金属丰度”（多组分合金的平均鲍林电负性的倒数）。当已知的IV、V和VI族合金的M-SCs的T - m标度温度与它们的金属丰度相对应时，曲线图直接指向所有已知的PCMs的组成区域和低于T - m的温度区间，这应该是发生转变的地方。金属丰度概念可以为定制pcm提供指导。
While fast-switching rewritable nonvolatile memory units based on phase-change materials (PCMs) are already in production at major technology companies such as Intel (16–64 GB chips are currently available), an in-depth understanding of the physical factors that determine their success is still lacking. Recently, we have argued for a liquid-phase metal-to-semiconductor transition (M-SC), located not far below the melting point, T _m, as essential. The M-SC is itself a consequence of atomic rearrangements that are involved in a fragile-to-strong viscosity transition that controls both the speed of crystallization and the stabilization of the semiconducting state. Here, we review past work and introduce a new parameter, the “metallicity” (inverse of the average Pauling electronegativity of a multicomponent alloy). When T _m-scaled temperatures of known M-SCs of Group IV, V, and VI alloys are plotted against their metallicities, the curvilinear plot leads directly to the composition zone of all known PCMs and the temperature interval below T _m, where the transition should occur. The metallicity concept could provide guidance for tailoring PCMs.