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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.

为了满足对微电子器件性能的持续改进的社会需求，存在对晶体管封装的持续驱动，使得空间封装密度可以被最大化。然而，工作功率密度的相关增加导致发热增加和片上温度升高，这可能会妨碍可靠的器件性能。这代表了巨大的技术挑战，并且明确需要识别和鉴定具有新的热性质的材料，其将能够实现纳米级的上级热能管理。特别是，利用外部刺激（例如电压）主动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产生重大影响。在铁电材料中，存在着原子级尖锐的结构界面，称为“畴壁”（DWs），它通过破坏热振动来阻碍热流。DWs的独特之处在于它们具有非凡的能力，可以通过施加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。这种性质提供了一种前所未有的手段，通过能够改变在给定时间存在于材料中的DW的数量以及它们的排列方式来主动控制热流。然而，要实现热流控制使用DW，明确的估计，在不同的材料中的DW提出的界面热阻必须首先确定。因此，本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。在此之后，将制造原型热装置，其中通过材料的热流的相对容易性将通过使用施加的电压来可逆地改变DW图案而改变。这也将为更长期的研究愿景提供基础，以创建一个更奇特的纳米结构“热镜”设备。在这种情况下，可以设想，DW可以被设计为充当热波的周期性反射器，以便最大限度地抑制热能，就像电介质镜中的多层如何高效反射光一样。在过去的十年中，人们已经清楚地认识到，DW可以被认为是一种新型的片状功能材料，其性质可以与散装材料显着不同。例如，当主体相对绝缘时，DW内的电传导可以是金属的，或者甚至是超导的。原型有源器件已经制造出来，其中功能完全来自导电DW的部署。然而，窄DW区域可能完全具有其自身的热性质的补充想法是全新的且未经探索的。在传导DW内，由于额外热载体（例如，移动的电子）的可用性，热流可能会增强，并且将进行热导率测量以确认这一点。传导DWs也将被探索用于将废热转换为电力，因为最近的预测表明，热电功率可以在DWs内提高高达100%，相比bulk.Overall，铁电DWs是令人兴奋的候选人，用作热设备中的有源元件，因为DWs可能在功能上表现为增强或限制热流。然而，这两种情况目前都没有得到很好的描述和理解。这些DW固有的可重构性意味着有真实的潜力来设计和构建基于铁电材料的新型有源热器件，而铁电材料尚未被利用。

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;

Regulation of thermal transport via ferroic interfaces

通过铁界面调节热传输