La<sub>3</sub>Pd<sub>2</sub>NaO<sub>9</sub>: A High-Valent Insulating Palladate
A high-valent palladate, La<sub>3</sub>Pd<sub>2</sub>NaO<sub>9</sub>, 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 <i>P</i>2<sub>1</sub>/<i>c</i> 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<sup>2+</sup> evidenced by XPS. The successful growth of La<sub>3</sub>Pd<sub>2</sub>NaO<sub>9</sub> 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<sub>3</sub>Ni<sub>2</sub>O<sub>7</sub>.
Authors
- Tao He (ORCID: https://orcid.org/0000-0002-3308-9107)
- Ning Guo (ORCID: https://orcid.org/0000-0002-3233-1555)
- Zheng Guo (ORCID: https://orcid.org/0000-0002-5828-8196)
- Qiang Zheng (ORCID: https://orcid.org/0000-0002-9279-7779)
- Feiyu Li (ORCID: https://orcid.org/0000-0003-1770-9473)
- Chuanyan Fan
- Tieyan Chang (ORCID: https://orcid.org/0000-0002-7434-3714)
- Lu Han (ORCID: https://orcid.org/0009-0009-1352-0076)
- Qingqing Yang (ORCID: https://orcid.org/0009-0000-2218-9316)
- Junjie Zhang (ORCID: https://orcid.org/0000-0002-5561-1330)
- Yu‐Sheng Chen (ORCID: https://orcid.org/0000-0001-6593-5155)
- Chao Liu (ORCID: https://orcid.org/0009-0006-9881-8768)
- Xiaoli Wang (ORCID: https://orcid.org/0009-0003-7020-1107)
Institutions
- Shandong University (CN)
- Center for NanoScience (DE)
- University of Chicago (US)
- Crystal Research (United States) (US)
- National Center for Nanoscience and Technology (CN)
- State Key Laboratory of Crystal Materials
Publication Details
- Journal
- Inorganic Chemistry
- Published
- 2025-06-30
- DOI
- https://doi.org/10.1021/acs.inorgchem.5c01833
- Primary Topic
- Magnetic and transport properties of perovskites and related materials
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China