Lamellar Crystal Structure and Haldane Magnetism in NH4 VPO4 OH

Aleksandr Sh Samarin; Ivan A Trussov; Zlata V Pchelkina; Stanislav S Fedotov; Yevgeniy A Ovchenkov; Sergei V Zhurenko; Alexei V Tkachev; Andrei A Gippius; Larisa V Shvanskaya; Alexander N Vasiliev

doi:10.1002/anie.202316719

Lamellar Crystal Structure and Haldane Magnetism in NH₄ VPO₄ OH

Angew Chem Int Ed Engl. 2024 Jan 15;63(3):e202316719. doi: 10.1002/anie.202316719. Epub 2023 Dec 14.

Authors

Affiliations

¹ Skolkovo Institute of Science and Technology, Bolshoi Boulevard 30 bld. 1, Moscow, 121205, Russia.
² M.N. Mikheev Institute of Metal Physics, UB RAS, S. Kovalevskaya street 18, Ekaterinburg, 620990, Russia.
³ Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira street 19, Ekaterinburg, 620002, Russia.
⁴ National University of Science and Technology "MISiS", Leninskiy Prospekt 4, Moscow, 119049, Russia.
⁵ Lomonosov Moscow State University, Leninskie Gory, GSP-1, Moscow, 119991, Russia.
⁶ Lebedev Physical Institute, RAS, Leninskiy Prospekt 53, Moscow, 119991, Russia.

PMID: 38054955
DOI: 10.1002/anie.202316719

Abstract

A novel vanadium hydroxide-phosphate, NH₄ VPO₄ OH, was synthesized hydrothermally in V₂ O₅ -NH₄ H₂ PO₄ -citric acid system at 230 °C. It was characterized by XRD, TG-DSC, SEM-EDX, FTIR and NMR spectroscopy. NH₄ VPO₄ OH is isostructural with NH₄ GaPO₄ OH and features edge-sharing chains of VO₆ octahedra. These chains running along [010] direction of the unit cell are connected by phosphate tetrahedra to form infinite layers parallel to the (100) plane. Ammonium cations are embedded between the heteropolyhedral layers. According to the thermodynamic and NMR measurements supported by the first-principles calculations, NH₄ VPO₄ OH presents a rare case of Haldane spin system with spin S=1 based on V³⁺ ions.

Keywords: Crystal Structure; Exchange Interactions; Hydrothermal Synthesis; Spin Gap; Spin Liquid.

Abstract

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