Large low-energy oscillator strength for Eu 4f electrons of a rare-earth Zintl compound: EuIn2P2

Nirpendra Singh, Joo Yull Rhee

Research output: Contribution to journalArticlepeer-review

Abstract

A newly found Zintl compound EuIn2P2 has been investigated within the density-functional theory, and results of a detailed investigation of its electronic structure and related properties are reported. We employed the so-called LSDA+U method (LSDA: local-spin-density approximation) with varying U from 0 eV to 7 eV to take into account the strong on-site Coulomb repulsion between the Eu 4f-electrons and to reproduce the semiconducting energy gap of 3.2 meV experimentally observed by J. Jiang and S. M. Kauzlarich [Chem. Mater. 18, 435 (2006)]. The calculations, however, could not reproduce the energy gap even for the largest U value of 7.0 eV because the experimental gap was not an optical gap, but it was deduced from the temperature dependence of resistivity at 26-60 K; thus, the experimental gap was not a real 'semiconducting' gap. The calculated optical-conductivity spectrum with U = 7.0 eV could not reproduce the experimental spectrum, while with simple LSDA, the calculated spectrum resembled the experimental one rather successfully. Therefore, it seems that the LSDA+U method is not suitable to correctly simulate the optical properties of this compound. Contrary to the expectation, we found that EuIn2P2 had a large oscillator strengths for f→d transitions in the low-energy range (below 1.5 eV); i.e., the peaks located at ~0.6 eV and ~1.1 eV in the experimental spectrum are mainly due to transitions from f-bands to d-bands, in which joint density-of-states effects play a key role. We also found that the magneto-optical Kerr effect was quite large in the EuIn2P2 compound.

Original languageEnglish (US)
Pages (from-to)2268-2274
Number of pages7
JournalJournal of the Korean Physical Society
Volume59
Issue number3
DOIs
StatePublished - Sep 15 2011
Externally publishedYes

Keywords

  • Density-functional calculations
  • Electronic structures
  • LSDA+U
  • Optical properties
  • Rare-earth Zintl compound

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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