Possible metal-insulator transition in a bismuth iridium oxide with the KSbO3-type structure
Possible metal-insulator transition in a bismuth iridium oxide with the KSbO3-type structure
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DOI：
10.1016/j.jallcom.2023.169435
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发表时间：
2023-02
影响因子：
6.2
通讯作者：
A. Belik;W. Yi
中科院分区：
文献类型：
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作者：
A. Belik;W. Yi
铱基化合物因其强大的自旋轨道耦合以及由此产生的奇异磁和电子特性而引起了广泛关注。我们在这里报告了一种高压、高温合成（在 6 GPa 和 1550 K 下）氧化铋铱的方法，其理想成分为 Bi3Ir3O11。该化合物结晶为 KSbO3 型结构，空间群为 Pn−3，晶格参数 a= 9.39556 Å（室温）。通过同步加速器粉末 X 射线衍射在 100 K 至 800 K 范围内研究晶体结构。直至 600 K 未发现结构相变或其他变化；高于 600 K 时，会发生部分分解，并出现少量 Ir 杂质。结构分析和密度测量表明 Bi3−δIr3−δO11 为缺阳离子成分，δ ≈ 0.11。在 2 K 到 400 K 之间观察到几乎与温度无关的顺磁行为。电阻率测量显示电阻率上升到约 85 K 以下，表明可能存在金属-绝缘体转变。没有观察到磁阻效应。
Iridium-based compounds have attracted a lot of attention because of strong spin-orbit coupling in them and resulting exotic magnetic and electronic properties. We report here a high-pressure, high-temperature synthesis (at 6 GPa and 1550 K) of a bismuth iridium oxide with the ideal composition of Bi3Ir3O11. This compound crystallizes in the KSbO3-type structure with space groupPn−3 and the lattice parametera= 9.39556 Å (at room temperature). The crystal structure was investigated by synchrotron powder X-ray diffraction between 100 K and 800 K. No structural phase transitions or other changes were found up to 600 K; above 600 K, a partial decomposition takes place with the appearance of a small amount of Ir impurity. The structural analysis and density measurements suggested a cation-deficient composition of Bi3−δIr3−δO11with δ ≈ 0.11. Nearly temperature-independent paramagnetic behavior was observed between 2 K and 400 K. Resistivity measurements showed a rise in resistivity below about 85 K suggesting a possible metal-insulator transition. No magnetoresistence effects were observed.