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设备性能持续改进的需求，晶体管微型化的驱动力持续不断，因此可以最大程度地提高空间堆积密度。但是，相关的运行功率密度增加会导致热量增加并在片上温度下降，从而可以防止可靠的设备性能。这是一个巨大的技术挑战，显然需要识别和表征具有新型的热特性的材料，从而可以在纳米级的上进行卓越的热能管理。特别是，用外部刺激（例如电压）积极控制热流的能力可能对下一代微电子的热管理需求和寿命具有显着影响。在这方面，氧化物铁电材料带来了令人兴奋的机会。在铁电材料中，存在原子上尖锐的结构界面，称为“域壁”（DWS），这些界面已知通过破坏热振动来阻碍热流。 DWS的独特之处在于它们通过使用施加的电压或压力以完全可逆的方式以完全可逆的方式在材料内部创建，擦除或重新定位的非凡能力。该特性提供了一种前所未有的手段，可以通过在给定时间及其排列方式改变材料中存在的DW数量来积极控制热流。但是，要使用DWS实现热流控制，必须首先确定由DWS在不同材料中提出的热界面电阻的确定估计值。因此，该项目的主要目标之一是通过直接导热率测量来量化DW热电阻。然后将鉴定具有有效抑制热流量的DWS的铁电体系系统。此后，将制造原型热设备，如果使用施加电压可逆地改变DW图案，则将更改通过材料的热流的相对易于性。这还将为长期研究视觉提供基础，以创建更奇特的纳米结构“热镜”设备。在这种情况下，可以预见，可以设计DWS作为热浪的定期反射器，以最大程度地拒绝热能，就像如何通过介电镜中的多层反射光的光反射。在过去的十年中，很明显，DW可以被视为一种新型的类似薄板的功能材料，其特性与大量可能非常不同。例如，当大容量相对绝缘时，DWS内的电传导可能是金属的，甚至是超导。原型主动设备已被制造，而功能完全源于电动导电DW的部署。但是，狭窄的DW区域可能完全具有自己的热性能的互补想法是全新的，尚未探索。在传导DWS中，由于额外的热载体（例如移动电子）的可用性，并且将进行热导率测量以确认这一点，因此很可能会增强热流量。还将探索将DWS转换为电力转换为电力，因为最近的预测表明，与批量相比，在DWS内，热电功率可以增强多达100％的dws。随后，由于DW可以在功能上以功能来增强功能或限制热量。但是，目前，案例均未得到很好的特征，也没有理解。这些DWS的先天可重新配置意味着，基于尚未大写的铁电材料设计和建造新型的活动热设备具有真正的潜力。

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