Using ferroelectric domain walls for active control of heat flow at the nanoscale

使用铁电畴壁主动控制纳米级热流

基本信息

批准号：
MR/T043172/1
负责人：
Raymond McQuaid
金额：
$ 122.68万
依托单位：
Queen's University Belfast
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=MR%2FT043172%2F1
关键词：
Using ferroelectric domain walls active

项目摘要

In order to satisfy societal demand for continual improvements in microelectronic device performance, there is an ongoing drive for transistor miniaturisation so that spatial packing densities can be maximised. However, the associated increases in operational power density leads to increased heat generation and rises in on-chip temperature that can prevent reliable device performance. This represents a tremendous technological challenge and there is a clear need to identify and characterise materials with novel thermal properties that will enable superior thermal energy management at the nanoscale. In particular, the ability to actively control heat flow with an external stimulus (e.g. voltage) could have dramatic implications for the thermal management demands and lifetimes of next generation microelectronics. In this regard, oxide ferroelectric materials present an exciting opportunity.In ferroelectric materials, there exist atomically sharp structural interfaces called 'domain walls' (DWs) that are known to impede heat-flow by disrupting thermal vibrations. What is unique about DWs is their remarkable ability to be created, erased or repositioned inside the material in a fully reversible way by using applied voltages or pressure. This property provides an unprecedented means to actively control heat flow by being able to alter the number of DWs present in the material at a given time and the way in which they are arranged. However, to realise heat flow control using DWs, definitive estimates for the thermal interfacial resistance presented by DWs in different materials must first be determined. Therefore, one of the main goals of this project is to quantify DW thermal resistances through direct thermal conductivity measurements. Ferroelectric material systems having DWs that effectively inhibit heat flow will then be identified. Following this, prototype thermal devices will be fabricated where the relative ease of heat flow through the material will be changed by using applied voltages to reversibly alter the DW pattern. This will also provide the foundation for a longer-term research vision to create a more exotic nanostructured 'thermal mirror' device. In this case, it is envisaged that DWs can be engineered to behave as periodic reflectors of thermal waves in order to maximise the rejection of thermal energy, much like how light is reflected with high efficiency by the multiple layers in a dielectric mirror. Over the last decade, it has become clear that DWs can be considered as a new type of sheet-like functional material with properties that can be remarkably different than bulk. For example, electrical conduction within DWs can be metallic, or even superconducting, when the bulk is comparatively insulating. Prototype active devices have been fabricated where functionality is derived entirely from deployment of electrically conducting DWs. However, the complementary idea that the narrow DW region may have thermal properties entirely of its own is completely new and unexplored. Within conducting DWs, it is likely that heat flow will be enhanced, due to the availability of extra heat carriers (e.g. mobile electrons), and thermal conductivity measurements will be carried out to confirm this. Conducting DWs will also be explored for conversion of waste heat into electricity since recent predictions indicate that the thermoelectric power can be enhanced by up to 100% within DWs, compared to bulk.Overall, ferroelectric DWs are exciting candidates for use as the active elements in thermal devices since the DWs may behave functionally to either enhance or restrict heat-flow. However, neither case is currently well characterised nor understood. The innate reconfigurability of these DWs means there is real potential to design and build new types of active thermal devices based on ferroelectric materials that has yet to be capitalised upon.

为了满足社会对微电子器件性能不断改进的需求，人们不断推动晶体管小型化，以使空间封装密度最大化。然而，工作功率密度的增加会导致发热增加和片上温度升高，从而影响器件性能的可靠性。这是一项巨大的技术挑战，显然需要识别和表征具有新颖热性能的材料，以实现纳米级的卓越热能管理。特别是，通过外部刺激（例如电压）主动控制热流的能力可能会对下一代微电子器件的热管理需求和寿命产生巨大影响。在这方面，氧化物铁电材料提供了一个令人兴奋的机会。在铁电材料中，存在称为“畴壁”（DW）的原子尖锐结构界面，已知它们会通过破坏热振动来阻碍热流。 DW 的独特之处在于它们具有通过使用施加的电压或压力以完全可逆的方式在材料内部创建、擦除或重新定位的卓越能力。这一特性提供了一种前所未有的方法来主动控制热流，能够改变给定时间材料中存在的 DW 数量及其排列方式。然而，为了使用 DW 实现热流控制，必须首先确定不同材料中 DW 所呈现的热界面热阻的明确估计。因此，该项目的主要目标之一是通过直接热导率测量来量化 DW 热阻。然后将确定具有有效抑制热流的 DW 的铁电材料系统。此后，将制造原型热器件，其中通过使用施加的电压可逆地改变 DW 图案来改变热流过材料的相对容易程度。这也将为创造更奇特的纳米结构“热镜”装置的长期研究愿景奠定基础。在这种情况下，可以设想将 DW 设计为热波的周期性反射器，以最大限度地抑制热能，就像介质镜中的多层高效反射光一样。在过去的十年中，人们已经清楚地认识到 DW 可以被视为一种新型片状功能材料，其特性与块状材料有显着不同。例如，当块体相对绝缘时，DW 内的导电可以是金属的，甚至是超导的。原型有源器件已经制造出来，其功能完全来自导电 DW 的部署。然而，窄 DW 区域可能完全具有自己的热特性这一补充想法是全新且未经探索的。在传导 DW 中，由于存在额外的热载体（例如移动电子），热流可能会增强，并且将进行热导率测量来证实这一点。还将探索传导 DW 将废热转化为电能，因为最近的预测表明，与散装相比，DW 内的热电功率可提高高达 100%。总体而言，铁电 DW 是用作活性元素的令人兴奋的候选者。热设备，因为 DW 的功能可能是增强或限制热流。然而，这两种情况目前都没有得到很好的描述和理解。这些数据仓库固有的可重构性意味着设计和构建基于铁电材料的新型有源热器件具有真正的潜力，但尚未得到充分利用。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

High resolution spatial mapping of the electrocaloric effect in a multilayer ceramic capacitor using scanning thermal microscopy

DOI：
10.1088/2515-7655/acf7f1
发表时间：
2023-09
期刊：
Journal of Physics: Energy
影响因子：
0
作者：
Olivia E Baxter;Amit Kumar;J. M. Gregg;R. G. McQuaid
通讯作者：
Olivia E Baxter;Amit Kumar;J. M. Gregg;R. G. McQuaid

Deterministic Dual Control of Phase Competition in Strained BiFeO3: A Multiparametric Structural Lithography Approach

DOI：
10.1007/s41871-021-00123-5
发表时间：
2021-12
期刊：
Nanomanufacturing and Metrology
影响因子：
0
作者：
Nathan Black;David Edwards;N. Browne;J. Guy;Niyorjyoti Sharma;Kristina M. Holsgrove;A. Naden;
通讯作者：
Nathan Black;David Edwards;N. Browne;J. Guy;Niyorjyoti Sharma;Kristina M. Holsgrove;A. Naden;

Conducting ferroelectric domain walls emulating aspects of neurological behavior