Increased electrical conduction with high hole mobility in anti-ThCr2Si2-type La2O2Bi via oxygen intercalation adjacent to Bi square net
Increased electrical conduction with high hole mobility in anti-ThCr2Si2-type La2O2Bi via oxygen intercalation adjacent to Bi square net
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DOI：
10.1063/5.0005300
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发表时间：
2020-05-11
影响因子：
4
通讯作者：
Fukumura, Tomoteru
中科院分区：
文献类型：
--
作者：
Matsumoto, Kota;Kawasoko, Hideyuki;Fukumura, Tomoteru
已知具有Bi正方形网的反ThCr2Si2型RE2O2Bi（RE =稀土）通过取代RE而显示绝缘体-金属转变。本文合成了不同氧非化学计量比的La_2O_2Bi多晶。随着La_2O_2Bi中氧含量的增加，c轴长度由于产生额外的4e位过剩氧而扩大，而a轴长度几乎保持不变，表明氧嵌入使Bi方网分离。与此同时，绝缘La2O2Bi转化为金属La2O2Bi发生的载流子极性从n型到p型的变化。尽管其多晶形式，具有最大量的氧的La2O2Bi显示出在其他层状氧磷属化合物和氧硫属化合物中相当高的空穴迁移率85 cm（2）V-1 s（-1）。
Anti-ThCr2Si2-type RE2O2Bi (RE = rare earth) with a Bi square net is known to show an insulator-metal transition by substituting RE. In this study, La2O2Bi polycrystals with different oxygen nonstoichiometry were synthesized. As the amount of oxygen in La2O2Bi increased, the c-axis length was expanded due to the generation of an additional 4e site for excess oxygen, while the a-axis length remained almost constant, indicating the separation of Bi square nets by oxygen intercalation. Concomitantly, transformation of insulating La2O2Bi into metallic La2O2Bi occurred with the change in carrier polarity from the n- to p-type. Despite its polycrystalline form, La2O2Bi with the largest amount of oxygen showed a rather high hole mobility of 85 cm(2) V-1 s(-1) among other layered oxypnictides and oxychalcogenides.