La_2Cu_(1-x)Zn_xO_(4+δ)低频内耗研究  

Low-frequency internal friction research on La_2Cu_(1-x)Zn_xO_(4+δ)

作　　者：陈志军[1] 吴修胜[2] 杨春利[1] 高海英[1] 刘卫[1] 

机构地区：[1]中国科学技术大学材料科学与工程系,安徽合肥230026 [2]安徽建筑工业学院材料与化学工程学院,安徽合肥230022

出　　处：《中国科学技术大学学报》2009年第7期694-698,共5页JUSTC

基　　金：国家自然科学基金(10574123;50332040)资助

摘　　要：对La2Cu1-xZnxO4+δ(0≤x≤0.2)系列样品的低频内耗和模量进行了研究.发现0≤x≤0.005时样品在低温存在两个弛豫内耗峰,分别是由样品中两种状态的额外氧跳跃弛豫引起的;当0.05≤x≤0.2时样品只存在一个内耗峰,该内耗峰可归于由共价氧对的额外氧跳跃引起,其峰位随掺杂量的增加向高温移动.不同掺杂量样品的模量曲线揭示高温处的模量反常对应着体系的正交-四方结构转变;此相变发生的温度随掺杂量的增加向高温移动.The low-frequency internal friction Q-1 and relative shear modulus M of La2Cu1-xZnxO4＋δ （0≤x≤0.2） compounds were studied. It was found that for 0≤x≤0. 005, there are two relaxation internal friction peaks around 200 K and 250 K, which are both due to the hopping of the excess O atoms; while for 0. 05≤x≤0. 2, only one relaxation peak exists around 250 K and this peak is due to the hopping of O pairs. The position of the structure phase transition revealed by shear modulus moves to higher temperature side with the increase of Zn content. In addition, the temperature of relaxation internal friction peaks also increases with the rise of Zn content.

关 键 词：La2Cu1-xZnxO4+δ 额外氧 内耗峰 相变 

分 类 号：O48[理学—固体物理]