Masamichi Nakajima, H. Yokota, Taihei Wakimura, Tetsuya Takeuchi, Koya Nakamura, M. Yashima, H. Mukuda, Shigeki Miyasaka, Setsuko Tajima
{"title":"Role of Vanadium-Oxide Layer in Electronic State of Sr2VFeAsO3−δ with Oxygen Deficiency","authors":"Masamichi Nakajima, H. Yokota, Taihei Wakimura, Tetsuya Takeuchi, Koya Nakamura, M. Yashima, H. Mukuda, Shigeki Miyasaka, Setsuko Tajima","doi":"10.7566/JPSJ.93.054711","DOIUrl":null,"url":null,"abstract":"Iron-based superconductor Sr$_2$VFeAsO$_3$ is composed of alternate stacking of a superconducting FeAs layer and an insulating vanadium-oxide layer with a perovskite-type structure. Electronic orders stemming from the spin and orbital degrees of freedom of V $3d$ electrons can arise in the vanadium-oxide layer, but such orders have not been confirmed so far. Here, we systematically investigate the electronic state of Sr$_2$VFeAsO$_{3-\\delta}$ with oxygen deficiency and demonstrate the phase diagram of Sr$_2$VFeAsO$_{3-\\delta}$ as a function of the $c$-axis lattice parameter, which has turned out to be a suitable measure of the amount of oxygen deficiency. We found a magnetic and structural anomaly at $\\sim 100$ K with a thermal hysteresis, which is manifested with the introduction of oxygen deficiency. The presence of orthorhombic distortion was revealed below the temperature at which the anomaly appears, suggestive of V orbital ordering involving the $d_{xz}$ and $d_{yz}$ orbitals. It seems that substantial fluctuations associated with the orthorhombic distortion significantly influence the electronic state of the FeAs layer. Our findings indicate that the vanadium-oxide layer plays a significant role in the electronic state of Sr$_2$VFeAsO$_{3-\\delta}$.","PeriodicalId":509167,"journal":{"name":"Journal of the Physical Society of Japan","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Physical Society of Japan","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.7566/JPSJ.93.054711","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Iron-based superconductor Sr$_2$VFeAsO$_3$ is composed of alternate stacking of a superconducting FeAs layer and an insulating vanadium-oxide layer with a perovskite-type structure. Electronic orders stemming from the spin and orbital degrees of freedom of V $3d$ electrons can arise in the vanadium-oxide layer, but such orders have not been confirmed so far. Here, we systematically investigate the electronic state of Sr$_2$VFeAsO$_{3-\delta}$ with oxygen deficiency and demonstrate the phase diagram of Sr$_2$VFeAsO$_{3-\delta}$ as a function of the $c$-axis lattice parameter, which has turned out to be a suitable measure of the amount of oxygen deficiency. We found a magnetic and structural anomaly at $\sim 100$ K with a thermal hysteresis, which is manifested with the introduction of oxygen deficiency. The presence of orthorhombic distortion was revealed below the temperature at which the anomaly appears, suggestive of V orbital ordering involving the $d_{xz}$ and $d_{yz}$ orbitals. It seems that substantial fluctuations associated with the orthorhombic distortion significantly influence the electronic state of the FeAs layer. Our findings indicate that the vanadium-oxide layer plays a significant role in the electronic state of Sr$_2$VFeAsO$_{3-\delta}$.