Presentation Information
[PC3-02-INV]Orbital Orders and Superconductivity in Anionic Honeycomb Superconductors La2IRu2 and La2IOs2
*Hajime Ishikawa1, Junichi Yamaura2, Ryosuke Kurihara1, Hajime Sagayama3, Mitsuaki Kawamura4 (1. Tokyo University of Science (Japan), 2. University of Tokyo (Japan), 3. High Energy Accelerator Research Organization (Japan), 4. Yokohama National University (Japan))
Keywords:
Honeycomb,Orbital Order,Ruthenate
Orbital degrees of freedom play a fundamental role in the physical properties of solids, including superconductors. An interesting feature of transition metal compounds is the formation of metal-metal bonds, which are often understood as a type of molecular orbitals. Metal-metal bonds are stabilized by the d-electrons occupying the bonding orbitals. As a result, antibonding orbitals do not play a significant role. Here, we investigate structural phase transitions in a superconducting honeycomb ruthenate La2IRu2, where antibonding Ru-4d orbitals are partially filled due to the anionic character of Ru. Upon cooling, we observed successive structural phase transitions preceding the superconductivity, which are understood as the ordering of anti-bonding 4d orbitals. Relationship between the orbital orders and superconductivity violating the Pauli-limit in La2IRu2 will be discussed, in comparison with the isostructural 5d analogue La2IOs2.
References
1) H. Ishikawa et al. Inorg. Chem. 58 12888 (2019).
2) H. Ishikawa et al. Phys. Rev. Mater. 7 054804 (2023).
References
1) H. Ishikawa et al. Inorg. Chem. 58 12888 (2019).
2) H. Ishikawa et al. Phys. Rev. Mater. 7 054804 (2023).