Year: 2025
Type: article
Abstract: A high-valent palladate, La 3 Pd 2 NaO 9, has been synthesized for the first time. Single crystals with dimensions of 20 μm on the edge were successfully grown using the flux method at 420 °C and 70 bar oxygen pressure. Energy dispersive spectroscopy (EDS) and inductively coupled plasma mass spectroscopy (ICP) measurements show that the atomic ratio of La: (Pd + Na) is 3:3 and Pd: Na is 2:1. X-ray photoelectron spectroscopy (XPS) measurements show that the oxidation state of Pd is dominated by the +4. Synchrotron X-ray single-crystal diffraction measurements revealed that this material crystallizes in the monoclinic P 2 1 / c space group with charge ordering of Na and Pd. Real-space imaging via scanning transmission electron microscopy (STEM) confirmed the crystal structure and revealed excellent sample homogeneity. Electrical resistivity measurements show an insulating behavior. Magnetic measurements show an unexpected paramagnetic behavior, which probably originates from a small fraction of high-spin Pd 2+ evidenced by XPS. The successful growth of La 3 Pd 2 NaO 9 single crystals with a high-valent oxidation state of Pd offers an approach for exploring interesting palladates, including potential bilayer Ruddlesden–Popper palladates analogous to the high temperature superconducting La 3 Ni 2 O 7 .
Source: Inorganic Chemistry
Authors: Qingqing Yang, Ning Guo, Tieyan Chang, Zheng Guo, Xiaoli Wang, Chuanyan Fan, Chao Liu, Lu Han, Feiyu Li, Tao He, Qiang Zheng, Yu-Sheng Chen, Junjie Zhang
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: G3248309569, G7733829741
OpenAlex ID: W4411778530