Electron Spin Resonance of Eu on triangular layers in EuT2P2 (T =Mn, Zn, Cd)

We report on the electron spin resonance (ESR) of Eu$^{2+}$ in Eu$T_{2}$P${2}$ ($T$=Mn, Zn, Cd) single crystals. The temperature dependencies of ESR linewidth and resonance shift show a similar behaviour when approaching the Eu-ordered state – a divergence towards $T{\rm N}$, indicating the growing importance of magnetic correlations and the build-up of internal magnetic fields. For $T$=Mn an additional temperature scale of $\approx 47$~K has considerable impact on linewidth, resonance field and intensity. This points to the presence of Mn magnetic correlations which yet were not reported.

💡 Research Summary

In this work the authors performed a systematic electron‑spin‑resonance (ESR) investigation of Eu²⁺ ions in single crystals of the trigonal 122‑type compounds EuT₂P₂ (T = Mn, Zn, Cd). The crystals were grown from Sn flux and measured with conventional continuous‑wave X‑band (≈9.4 GHz) and Q‑band (≈34.1 GHz) spectrometers over a broad temperature range from 5 K to 500 K. All three materials display a single, well‑resolved Lorentzian ESR line, confirming that the Eu ions retain their localized 4f⁷ configuration.

At room temperature the g‑values are close to 2.0 (1.976–2.003), in line with previous reports on Eu‑pnictides. The ESR intensity follows a Curie‑Weiss law, I_ESR ∝