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arXiv · 2306.10883

The 3d and 5d electronic structures and orbital hybridization in Ba- and Ca-doped La2CoIrO6 double perovskite

J. R. L. Mardegan·L. S. I. Veiga·T. Pohlmann·S. S. Dhesi·S. Francoual·J. R. Jesus·C. Macchiutti·E. M. Bittar·L. Bufaiçal
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Abstract

Here we present a detailed investigation of the Co and Ir local electronic structures in La1.5A0.5CoIrO6 (A = Ba, Ca) compounds in order to unravel the orbital hybridization mechanism in these CoIr-based double perovskites. Our results of x-ray powder diffraction, ac and dc magnetization, Co and Ir L2,3-edges and Co K-edge x-ray absorption spectroscopy and x-ray magnetic circular dichroism suggest a competition between magnetic interactions. A dominant antiferromagnetic coupling is found to be responsible for the ferrimagnetic behavior observed for A = Ca below approximately 96 K, the competing magnetic phases and the cationic disorder in this compound giving rise to a spin-glass state at low temperatures. For the A = Ba, on the other hand, there is no evidence of long range order down to its spin-glass transition temperature. The remarkably different magnetic properties observed between these two compounds is discussed in terms of the structural distortion that alters the strength of the Co - Ir couplings, with a relevant role played by the Co 3d eg - Ir 5d j = 1/2 hybridization.

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J. R. L. Mardegan, L. S. I. Veiga, T. Pohlmann, S. S. Dhesi, S. Francoual, J. R. Jesus, C. Macchiutti, E. M. Bittar, L. Bufaiçal. 2023-06-19. The 3d and 5d electronic structures and orbital hybridization in Ba- and Ca-doped La2CoIrO6 double perovskite. https://doi.org/10.1103/physrevb.107.214427

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