Fragile-to-Strong Transitions in Phase-Change Materials for Next-Generation Memory Devices

非技术描述：随着信息技术的指数增长，存储海量数据的能力正在成为一种主要的社会需求。相变材料是未来数据存储应用中最有前途的材料之一。它们是实现高密度光学数据存储的关键部件，例如可重写DVD(数字多功能盘)和非易失性计算机存储器(相变随机存取存储器(PC-RAM))。然而，它们目前受到老化问题的困扰，随着时间的推移，这些问题会导致性能下降，最终导致数据丢失。这项研究的目的是开发新一代相变材料，使其免受这种数据丢失现象的影响。此外，这种材料可以使依赖于高度稳定的相变材料的新兴技术(高密度多级存储器和超快的人工神经元类处理器)成为可能。在进行这项研究的过程中，研究生正在接受材料科学和工程领域的培训。在微电子工业等高科技领域，材料专业知识的需求很高。技术细节：相变材料的发现表现出明显的从脆弱到强大的转变，这是开发不受当前困扰存储技术的数据丢失现象影响的存储设备的关键。这些新材料的发现是通过表征相变材料家族的热力学和结构行为而实现的。目标是找出不受结构松弛影响的材料。这些材料是实现新兴技术的关键，这些技术依赖于物理性质的部分变化，并且对漂移特别敏感。因此，这项研究支持开发变革性的新技术，如用于超快计算的人工神经网络处理器。从根本上讲，这项研究提供了从脆弱到强大转变的关键洞察力，并回答了玻璃科学中悬而未决的相关问题，如β-松弛和多晶性的起源。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: With the exponential growth of information technologies, the ability to store huge amounts of data is becoming a major societal need. Phase-change materials are some of the most promising materials for future data-storage applications. They are the key component enabling high density optical data storage such as rewritable DVD (digital versatile disc) and nonvolatile computer memories (phase-change random access memory (PC-RAM)). However, they currently suffer from aging issues that lead to degradation over time and eventually to data loss. This research aims at developing a new generation of phase-change materials that are immune to this data-loss phenomenon. Moreover, such materials can enable emerging technologies (high density multilevel memories and ultrafast, artificial neuron-like processors) that rely on highly stable phase-change materials. Through the process of conducting this research, graduate students are being trained in the field of materials science and engineering. Materials expertise is in high demand in high technology sectors such as the microelectronic industry.TECHNICAL DETAILS: The discovery of phase-change materials exhibiting a pronounced fragile-to-strong transition is key to the development of memory devices that are immune to the data-loss phenomenon currently plaguing memory technologies. The discovery of these new materials is achieved by characterizing the thermodynamic and structural behavior of families of phase change materials. The goal is to identify materials that are immune to structural relaxation. These materials are key in enabling emerging technologies that rely on fractional changes in physical properties and are particularly sensitive to drift. This research therefore supports the development of transformational new technologies such as artificial neural-network processor for ultra-fast computing. From a fundamental point of view, this research provides key insight into the origin of fragile-to-strong transitions and answers outstanding related questions in glass science such as the origin of beta-relaxation and polyamorphism.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.