| Autor: |
Namba, Morito, Takatsu, Hiroshi, Murayama, Kantaro, Shibazaki, Yuki, Ishimatsu, Naoki, Ubukata, Hiroki, Terada, Ryo, Yoshimura, Noriyuki, Kawanishi, Shohei, Terashima, Takahito, Kageyama, Hiroshi |
| Zdroj: |
Chemistry of Materials; 20240101, Issue: Preprints |
| Abstrakt: |
Perovskite oxyhydride EuVO2H exhibits a Mott insulating state derived from VIIIO2layers and a ferromagnetic state derived from EuIIH layers, with compressive strain inducing intersite charge transfer (ICT) in thin films, accompanied by an increased ferromagnetic transition temperature (TC) and the emergence of perpendicular magnetic anisotropy (PMA). While ICT has previously been adjusted by film thickness (or substrate strain), this study demonstrates its control by Eu-site substitution with Sr. Utilizing topochemical hydride reduction, we fabricated Eu1–xSrxVO2H solid solution thin films on SrTiO3substrates, providing −0.6% compressive strain. With an increasing Sr content, the Eu valence remains almost unchanged, indicating a reduced level of electron transfer from the Eu 4f band to the V 3dxyband. This observation is ascribed to the reduced dispersion of the Eu 4f band, in contrast with our previous study on EuVO2H in which the empty V 3dxybandwidth was manipulated by film thickness, manifesting the possibility of independent control over the d band and f band, an achievement unexplored in previous oxide research. Sr substitution not only decreases TCbut also suppresses PMA. In addition, the application of high pressure to Eu0.9Sr0.1VO2H powder induces a continuous valence evolution of Eu, as opposed to that of pristine EuVO2H, which undergoes a first-order valence transition. This study offers possibilities for independent control of the electronic structure of systems containing both transition metals and rare earth elements. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
