Magnetic cluster behavior of α-LiFeO2 related to the cation arrangements
Magnetic cluster behavior of α-LiFeO2 related to the cation arrangements
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DOI：
10.1143/jjap.43.l1232
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发表时间：
2004-09-15
期刊：
影响因子：
--
通讯作者：
Bando, Y
中科院分区：
文献类型：
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作者：
Kohiki, S;Hori, K;Bando, Y
在透射电子显微镜的α-LiFeO 2，我们发现的立方结构（a = 4.2埃）和双晶胞结构（a = 8.3埃）与波浪形漫散射由于短程有序的Li+和Fe 3+离子的电子衍射图案。一个不寻常的磁状态与共存的现象有关的磁有序和玻璃态行为的交流和直流磁化率观察α-LiFeO 2。零场冷却磁化率的分叉点约为90 K，最大温度约为40 K。在90 K以下，场冷磁化率随温度的降低而单调增加，零场冷磁化率随温度的降低而低于场冷磁化率。同相交流磁化率在90 K附近有一个尖点，在60 K附近有一个宽肩。三次谐波非线性极化率在200 K以下没有明显的尖峰.观察到的α-LiFeO 2的磁性行为可以理解为铁磁簇的形成，簇内Fe 3+自旋的短程有序，以及簇的逐渐冻结。这种不寻常的玻璃化行为是由于α-LiFeO 2中立方结构的短程有序。
In transmission electron microscopy of alpha-LiFeO2, we found electron diffraction patterns of both cubic structure (a = 4.2 Angstrom) and doubled unit cell structure (a = 8.3 Angstrom) with wavy shaped diffuse scattering due to short-range ordering of Li+ and Fe3+ ions. An unusual magnetic state with coexistence of phenomena related to magnetic ordering and glassy behavior in the ac and dc susceptibilities was observed for alpha-LiFeO2. The bifurcation point was approximate to90 K, and the temperature of a broad maximum in the zero-field cooled susceptibility was approximate to40 K. Below approximate to90 K, the field cooled susceptibility increased monotonically and the zero-field cooled susceptibility deviated below the field cooled one with lowering the temperature. The in-phase ac susceptibility demonstrated a cusp at approximate to90 K with a broad shoulder around 60 K. The third harmonic nonlinear susceptibility showed no sharp peak below 200 K. Observed magnetic behavior of alpha-LiFeO2 can be understood as formation of ferromagnetic clusters, with short-range ordering of Fe3+ spins within the clusters, and progressive freezing of the clusters. The unusual glassy behavior is due to the short-range ordering of cubic structure in alpha-LiFeO2.