La_2NiO_(4+δ)体系相分离现象的低频内耗研究  

Phase separation in La_2NiO_(4+δ) studied by low-frequency internal friction technique

作　　者：张华力[1] 刘卫[1] 李栋才[1] 吴修胜[1] 陈初升[1] 

机构地区：[1]中国科学技术大学材料科学与工程系,合肥230026

出　　处：《物理学报》2004年第11期3834-3838,共5页Acta Physica Sinica

基　　金：国家自然科学基金重点项目 (批准号 :5 0 3 3 2 0 40 )资助的课题~~

摘　　要：La2 NiO4 +δ体系额外氧δ =0 .0 71,0 .110 ,0 .135 ,0 .14 0样品中存在着一个间隙氧弛豫运动引起的低频内耗峰 ,其内耗峰峰位置随额外氧的增多向高温移动 .而额外氧处于其间位置δ =0 .0 87样品中则出现了两个弛豫型内耗峰 ,分析认为它们源于体系相分离后形成的不同一维有序结构中间隙氧的跳跃 .此外 ,额外氧δ=0 .0 38样品中也观察到两个弛豫型内耗峰 ,其中低温峰性质与上相同 。There exists a low_frequency relaxation internal friction peak in La 2NiO 4+δ with δ=0.071, 0.110, 0.135 and 0.140, the peak position shifting to higher temperature, when more excess oxygen is incorporated. At δ=0.087 two peaks were observed which may be attributed to the jump of the interstitial oxygen atoms in the different kind of the one_dimensional ordering phase formed by phase separation. At δ=0.038 two peaks were also observed which may be attributed to the jump of the interstitial oxygen atoms in the low_temperature tetragonal phase and the one-dimensional ordering phase formed by phase separation.

关 键 词：弛豫 相分离 氧原子 一维 跳跃 样品 有序结构 观察 运动 中低温 

分 类 号：O614[理学—无机化学]