Avilov Vadim I, Tominov Roman V, Vakulov Zakhar E, Rodriguez Daniel J, Polupanov Nikita V, Smirnov Vladimir A
Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia.
Department of Radioelectronics and Nanoelectronics, Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia.
Nanomaterials (Basel). 2025 Jan 6;15(1):75. doi: 10.3390/nano15010075.
This paper presents the results of a study on the formation of nanostructures of electrochemical titanium oxide for neuromorphic applications. Three anodization synthesis techniques were considered to allow the formation of structures with different sizes and productivity: nanodot, lateral, and imprint. The mathematical model allowed us to calculate the processes of oxygen ion transfer to the reaction zone; the growth of the nanostructure due to the oxidation of the titanium film; and the formation of TiO, TiO, and TiO oxides in the volume of the growing nanostructure and the redistribution of oxygen vacancies and conduction channel. Modeling of the nanodot structure synthesis process showed that at the initial stages of growth, a conductivity channel was formed, connecting the top and bottom of the nanostructure, which became thinner over time; at approximately 640 ms, this channel broke into upper and lower nuclei, after which the upper part disappeared. Modeling of the lateral nanostructure synthesis process showed that at the initial stages of growth, a conductivity channel was also formed, which quickly disappeared and left a nucleus that moved after the moving AFM tip. The simulation of the imprint nanostructure synthesis process showed the formation of two conductivity channels at a distance corresponding to the dimensions of the template tip. After about 460 ms, both channels broke, leaving behind embryos. The nanodot, lateral, and imprint nanostructure XPS spectra confirmed the theoretical calculations presented earlier: in the near-surface layers, the TiO oxide was observed, with the subsequent titanium oxide nanostructure surface etching proportion of TiO decreasing, and proportions of TiO and TiO oxides increasing. All nanodot, lateral, and imprint nanostructures showed reproducible resistive switching over 1000 switching cycles and holding their state for 10,000 s at read operation.
本文介绍了一项关于用于神经形态应用的电化学氧化钛纳米结构形成的研究结果。考虑了三种阳极氧化合成技术，以形成具有不同尺寸和生产率的结构：纳米点、横向和压印。数学模型使我们能够计算氧离子转移到反应区的过程；由于钛膜氧化导致的纳米结构生长；以及在生长的纳米结构体积中TiO、TiO和TiO氧化物的形成以及氧空位和导电通道的重新分布。纳米点结构合成过程的建模表明，在生长的初始阶段，形成了一个导电通道，连接纳米结构的顶部和底部，随着时间的推移该通道变窄；在大约640毫秒时，该通道分裂成上下核，之后上部消失。横向纳米结构合成过程的建模表明，在生长的初始阶段，也形成了一个导电通道，该通道很快消失并留下一个核，该核跟随移动的原子力显微镜尖端移动。压印纳米结构合成过程的模拟表明，在与模板尖端尺寸对应的距离处形成了两个导电通道。大约460毫秒后，两个通道都断裂，留下胚胎。纳米点、横向和压印纳米结构的XPS光谱证实了先前提出的理论计算：在近表面层中，观察到TiO氧化物，随后钛氧化物纳米结构表面的TiO蚀刻比例降低，而TiO和TiO氧化物的比例增加。所有纳米点、横向和压印纳米结构在1000个开关周期内均表现出可重复的电阻切换，并在读取操作时保持其状态10000秒。
