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arXiv · 2505.21995

Sr$_2$NbO$_4$: A $4d$ analogue of the layered perovskite Sr$_2$VO$_4$

Leonid S. Taran·Anastasia E. Lebedeva·Sergey V. Streltsov
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Abstract

This work focuses on the layered perovskite Sr$_2$NbO$_4$, a 4$d$ analogue of Sr$_2$VO$_4$, which remains an unsolved puzzle with a possible intriguing hidden magnetic order. Using density functional theory (DFT) calculations, we demonstrate the robust thermodynamic stability and exfoliability of Sr$_2$NbO$_4$, suggesting potential applications as a 2D material. Imperfect Fermi surface nesting indicates instabilities that may drive symmetry lowering, charge/orbital density waves, or superconductivity. Dynamical mean-field theory (DMFT) calculations reveal moderate mass renormalization $(m^*/m\sim1.3)$ and an itinerant character of magnetism with strong longitudinal spin fluctuations. The exchange interaction is dominated by in-plane ferromagnetic coupling with much weaker interlayer antiferromagnetic exchange.

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Leonid S. Taran, Anastasia E. Lebedeva, Sergey V. Streltsov. 2025-05-28. Sr$_2$NbO$_4$: A $4d$ analogue of the layered perovskite Sr$_2$VO$_4$. https://doi.org/10.1103/physrevb.111.245121

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