Diffusion of dopants in rutile is the fundamental process that determines the performance of many devices in which rutile is used. The diffusion behavior is known to be highly sample-dependent, but the reasons for this are less well understood. Here, rutile is studied by using first-principles calculations, in order to unravel the microscopic origins of the diverse diffusion behaviors for different doping elements. Anomalous diffusion behavior in the open channel along [001] direction is found: larger atoms include Sc and Zr have lower energy barrier for diffusion via interstitial mechanism, apparently contradicting their known slow diffusion rate. To resolve this, we present an alternate model for the overall diffusion rate of the large-size dopants in rutile, showing that parallel to the [001] channel, it is limited by the formation of the interstitial states, whereas in the direction perpendicular to [001], it proceeds via a kick-out mechanism. By contrast, Co and Ni, prefer to stay in the interstitial site of rutile, and have conventional diffusion with a very small migration barrier in the [001] channel. This leads to highly anisotropic and fast diffusion. The diffusion mechanisms found in the present study can explain the diffusion data measured by experiments, and these findings provide novel understanding for the classic diffusion topic.
Microscopic Origin of Temperature-Dependent Anisotropic Heat Transport in Ultrawide-Bandgap Rutile GeO2
Technische Universität Berlin（柏林工业大学）；Department of Physics, Universidade Federal do Ceará（塞阿拉联邦大学物理系）；Leibniz-Institut für Kristallzüchtung（莱布尼茨晶体生长研究所）
Nitrogen doping induced metal-insulator transition with iso-symmetric character in rutile VO2
Harbin Institute of Technology, Shenzhen（哈尔滨工业大学（深圳））；Minjiang University（闽江大学）；Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area（粤港澳大湾区量子科学中心）；University of Science and Technology Beijing（北京科技大学）；Helmholtz-Zentrum Dresden – Rossendorf（德累斯顿罗森多夫亥姆霍兹中心）；University of Science and Technology of China（中国科学技术大学）；Soochow University（苏州大学）；National Yang Ming Chiao Tung University（国立阳明交通大学）；Indian Institute of Science（印度科学学院）；The School of Integrated Circuit, Harbin Institute of Technology, Shenzhen（哈尔滨工业大学（深圳）集成电路学院）；Max-Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）；National Synchrotron Radiation Research Center（国家同步辐射研究中心）；Nanyang Technological University（南洋理工大学）
Interface-induced collective phase transition in VO2-based bilayers studied by layer selective spectroscopy
Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University（东北大学先进材料多学科研究所）；Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)（高能加速器研究机构物质结构科学研究所光子工厂）；Institut des Sciences Moléculaires d’Orsay, Université Paris-Saclay（巴黎萨克雷大学奥赛分子科学研究所）
