Structure and physical properties of CsV2Se2−xO and V2Se2O
| Autor: | Lu Kong, Hai-Hu Wen, Hao Li, Hai Lin, Xiaodong Yu, Jin Si, Xiyu Zhu, Kehan Cai |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Physical Review B. 98 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | By using solid-state reactions, we successfully synthesize new oxyselenides ${\mathrm{CsV}}_{2}{\mathrm{Se}}_{2\ensuremath{-}x}\mathrm{O}$ ($x=$ 0, 0.5). These compounds containing ${\mathrm{V}}_{2}\mathrm{O}$ planar layers with a square lattice crystallize in the ${\mathrm{CeCr}}_{2}{\mathrm{Si}}_{2}\mathrm{C}$ structure with the space group of $P4/mmm$. Another new compound, ${\mathrm{V}}_{2}{\mathrm{Se}}_{2}\mathrm{O}$, which crystallizes in space group $I4/mmm$ is fabricated by topochemical deintercalation of cesium from ${\mathrm{CsV}}_{2}{\mathrm{Se}}_{2}\mathrm{O}$ powder with iodine in tetrahydrofuran. Resistivity measurements show a semiconducting behavior for ${\mathrm{CsV}}_{2}{\mathrm{Se}}_{2}\mathrm{O}$, while a metallic behavior for ${\mathrm{CsV}}_{2}{\mathrm{Se}}_{1.5}\mathrm{O}$, and an insulating feature for ${\mathrm{V}}_{2}{\mathrm{Se}}_{2}\mathrm{O}$. A charge- or spin-density-wave like anomaly has been observed at 168 K for ${\mathrm{CsV}}_{2}{\mathrm{Se}}_{2}\mathrm{O}$ and 150 K for ${\mathrm{CsV}}_{2}{\mathrm{Se}}_{1.5}\mathrm{O}$, respectively. These anomalies are also confirmed by the magnetic susceptibility measurements. The resistivity in ${\mathrm{V}}_{2}{\mathrm{Se}}_{2}\mathrm{O}$ exhibits an anomalous log(1/$T$) temperature dependence, which is similar to the case in parent phase or very underdoped cuprates indicating the involvement of strong correlation. Magnetic susceptibility measurements show that the magnetic moment per V site in ${\mathrm{V}}_{2}{\mathrm{Se}}_{2}\mathrm{O}$ is much larger than that of ${\mathrm{CsV}}_{2}{\mathrm{Se}}_{2\ensuremath{-}x}\mathrm{O}$, which again suggests the correlation-induced localization effect in the former. |
| Databáze: | OpenAIRE |
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