Anomalous compression and new high-pressure phases of vanadium sesquioxide, V2O3
Anomalous compression and new high-pressure phases of vanadium sesquioxide, V2O3
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DOI：
10.1088/0953-8984/25/38/385401
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发表时间：
2013-08
期刊：
影响因子：
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通讯作者：
S. Ovsyannikov;D. Trots;A. Kurnosov;W. Morgenroth;H. Liermann;L. Dubrovinsky
中科院分区：
文献类型：
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作者：
S. Ovsyannikov;D. Trots;A. Kurnosov;W. Morgenroth;H. Liermann;L. Dubrovinsky
我们报告了在高达 57 GPa 的氖压力传输介质中加压下三氧化二钒 (V2O3) 的粉末 X 射线衍射 (XRD) 研究结果。我们已经确定了刚玉型 V2O3 在 B′ = 4 时的体积模量值为 B0 = 150 GPa。该体积模量值是已知的刚玉型结构氧化物中最低的，例如Al2O3、α-Fe2O3、Cr2O3、Ti2O3 和 α-Ga2O3。我们提出这可能与电子能带结构的差异有关：在室温下，V2O3 是金属性的，但上述刚玉结构的倍半氧化物是半导体或绝缘的。大约~21-27和~50 GPa，我们记录了可能与相变有关的 XRD 图案的变化。这些转变在室温压缩下是缓慢的，因此我们还通过激光加热一个样品来促进它们。我们仅改进了 Rh2O3(II) 型斜方晶格中第一高压相的 XRD 图案。我们的研究结果显着扩展了对 V2O3 P-T 相图的了解，并加深了对其性质的理解。我们推测，V2O3 的弹性性质与其电子能带结构密切相关，因此，我们提出，轻微掺杂的 V2O3（例如 Cr）可能是体积模量值可以通过中等压力或温度显着改变的系统的潜在候选者。
We report results of a powder x-ray diffraction (XRD) study of vanadium sesquioxide, V2O3, under pressurization in a neon pressure-transmitting medium up to 57 GPa. We have established a bulk modulus value for corundum-type V2O3 of B0 = 150 GPa at B′ = 4. This bulk modulus value is the lowest among those known for the corundum-type-structured oxides, e.g. Al2O3, α-Fe2O3, Cr2O3, Ti2O3, and α-Ga2O3. We have proposed that this might be related to the difference in the electronic band structures: at room temperature V2O3 is metallic, but the above corundum-structured sesquioxides are semiconducting or insulating. Around ∼21–27 and ∼50 GPa we registered changes in the XRD patterns that might be addressed to phase transitions. These transitions were sluggish upon room-temperature compression, and hence we additionally facilitated them by the laser heating of one sample. We have refined the XRD patterns of only the first high-pressure phase in an orthorhombic lattice of a Rh2O3(II)-type. Our findings significantly extend the knowledge of the P–T phase diagram of V2O3 and advance the understanding of its properties. We speculate that the elastic properties of V2O3 can be closely linked to its electronic band structure and, consequently, we propose that slightly doped V2O3 (e.g. with Cr) could be a potential candidate for systems in which the bulk modulus value may be remarkably switched by moderate pressure or temperature.